You need to solve a system of equations. You decide to use the elimination method. Which of these is not allowed? 2x - 3y = 12
-x + 2y = 13
O A. Multiply the left side of equation 2 by 2. Then subtract the result from equation 1.
O B. Multiply equation 1 by 2 and equation 2 by 3. Then add the new equations.
C. Multiply equation 2 by-2. Then add the result to equation 1. ​

Answers

Answer 1

Answer:

A.

Step-by-step explanation:

The Elimination Method is the method for solving a pair of linear equations which reduces one equation to one that has only a single variable.

If the coefficients of one variable are opposites, you add the equations to eliminate a variable, and then solve.

If the coefficients are not opposites, then we multiply one or both equations by a number to create opposite coefficients, and then add the equations to eliminate a variable and solve.

When multiplying the equation by a coefficient, we multiply both sides of the equation (multiplying both sides of the equation by some nonzero number does not change the solution).

So, option B is not allowed (it is not allowed to multiply only one part of the equation)


Related Questions

If a number is divisible by 6 and 8 then is it also divisible by 48?

Answers

Answer:

No

Step-by-step explanation:

Let's look at an example

24

24 is divisible by 6   24/6 = 4  

24 is divisible by 8   24/8 = 3

24 is not divisible by 48  24/48 = 1/2  which is not an integer

On her summer abroad in France, Jane bought a pair of shoes for 54.82 euros. The store owner only had francs to give her as change. She gave him 55 euros. How much did he give her back in francs

Answers

Answer:

0.19

Step-by-step explanation:

Jane bought a shoe for 54.82 euros

She gave the store owner 55 euros

= 55-54.82

= 0.18 euros to franc

= 0.18× 1.08222

= 0.19 franc

The population of a strain of bacteria doubles in a culture. At noon there were 80 bacteria present and by 4:00 PM there were 20 480 bacteria. Determine algebraically the doubling period. Hint: You DO NOT need to use systematic trials.

Answers

Answer:

t = 1/2 hour

Step-by-step explanation:

20480 = 80[tex]x^{t }[/tex]

20480 = 80[tex]x^{4 }[/tex]

20480/80  =  [tex]x^{4 }[/tex]

256 =  [tex]x^{4 }[/tex]

x = 4

doubling period

2 = [tex]4^{t}[/tex]

t = 1/2 hour

what is x divided by one​

Answers

Answer:

[tex] x \div 1[/tex]

[tex] = x[/tex]

Answer:

[tex]x\div 1=x[/tex]

Step-by-step explanation:

When x is divided by one it is called reciprocal.

reciprocal is the inverse of a number or a value.

examples: The reciprocal of 3 is 1/3, and the reciprocal of 5 is 1/3.

OAmalOHopeO

if (a + b) = 73 and a b =65 find value of a²+ b²​

Answers

Step-by-step explanation:

Here,

by formula a^2+b^2=(a+b)^2-2ab

so,

or,(a+b)^2-2ab

or,(73)^2-2×65

or,5329-126

=5203 is the answer

An item is regularly priced at$15.It is now priced at a discount of55%off the regular price

Answers

Answer:

$6.75

Step-by-step explanation:

The regular price is $15 dollars. The discount is 55% off the $15.

15 * 0.55 = 8.25

15 - 8.25 = 6.75

Hope this helps.

Answer:

discount =8.25

New price 6.75

Step-by-step explanation:

15 is the regular price

The discount is 55%

15*.55

8.25

The new price is the regular price minus the discount

15-8.25

6.75

Rewrite the fraction in the sentence below as a percentage. From 125 yards away, a marksman hit 11/20 of the targets last year.

Answers

Answer:

Step-by-step explanation:

11/20 = 55/100 = 55%

55%

11/20 is .55, which in percentage form is simply 55%.

Hope this helps! Please make me the brainliest, it’s not necessary but appreciated, I put a lot of effort and research into my answers. Have a good day, stay safe and stay healthy.

Solve equation by using the quadratic formula

Answers

Answer:

x = -2

Step-by-step explanation:

x^2 + 4x + 4 = 0

quadratic formula:

-b +or- sqrt(b^2-4ac)/2a

-4 +/- sqrt ((-4)^2-4*1*4)/2*1

-4+/- sqrt(16-16) / 2

-4 +/- 0 / 2

-4/2

-2

Please help due tomorrow

Answers

Answer: x= 2.5, y = 10

Step-by-step explanation:

I'm going to assume that these photocopies are proportional in relations to each other.

If they're proportional, you can set up two proportions:

[tex]1) \frac{x}{5} =\frac{3}{6} \\\\2) \frac{5}{y} =\frac{3}{6}[/tex]

And cross-multiply:

[tex]1) 6x = 5*3 \\\\2) 3y = 5*6[/tex]

Then solved for x and y:

[tex]1) 6x = 15\\x=\frac{15}{6} =\frac{5}{2} =2.5 \\\\2) 3y = 30\\y=\frac{30}{3} =10[/tex]

Question 4 please provide explanation for question

Answers

Answer:

A

Step-by-step explanation:

We need to find a equation that is where the domain is all real numbers and the range is all real numbers greater than -3

A square root function cannot equal to all real numbers because we cant take the square root of a negative number. so B and C are already wrong.A cubic function range is all real numbers. so y can be greater than -3 but it would also include. values lesser than -3. so D is Wrong.

A is right, the domain of a absolute value function is all real numbers. The range of a absolute value is all numbers greater than or equal to zero but if we subtract 3, it changes into all real numbers greater than or equal to -3

Zelina scored 10% higher on her second quiz than on her first quiz. On her third quiz, Zelina scored 20% higher than on her second quiz. Her third quiz score is what percent higher than her first quiz score?

Answers

Answer:

30%

Step-by-step explanation:

you just add 10% and 20%

Hope it helps c:

Zelina scored 32% higher on the third quiz than on her first quiz.

What is the percentage?

The Percentage is defined as representing any number with respect to 100. It is denoted by the sign %.

Given that:-

Zelina scored 10% higher on her second quiz than on her first quiz. On her third quiz, Zelina scored 20% higher than on her second quiz.

From the given data we will see that:-

1 ) Zelina scored 10% higher on her second quiz than on her first quiz.

SQ = 1.10 FQ

2 ) On her third quiz, Zelina scored 20% higher than on her second quiz

TQ = 1.20SQ

From the above to expression solve for the first quiz:-

TQ = 1.20 x  1.10 FQ

TQ = 1.32FQ

Therefore Zelina scored 32% higher on the third quiz than on her first quiz.

To know more about percentages follow

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Simplify the trigonometric expression cos(2x)+1 using Double-Angle identities

Answers

9514 1404 393

Answer:

  C.  2cos²(x)

Step-by-step explanation:

The relevant identities are ...

  cos(2x) = cos²(x) -sin²(x)

  cos²(x) = 1 -sin²(x)

__

Then the expression can be simplified to ...

  cos(2x) +1 = (cos²(x) -sin²(x)) +1 = cos²(x) +(1 -sin²(x)) = cos²(x) +cos²(x)

  = 2cos²(x)

Think of a two-digit number. What is the probability that it has different digits?

Answers

Answer:

9/10

Step-by-step explanation:

The first two digit number is 10 and the last is 99. That's a total of 99-10+1 numbers in all. That simplifies to 90. (Just like if we wanted to see how many numbers was 3,4,5, we would do 5-3+1=3 to get the total number.

Anyways, let's consider first how many 2 digjt numbers whose digits are equal. You have 11 22,33,44 55,66,77,88,99 which is 9 numbers total.

So the amount of 2 digits number whose digits differ is 90-9=81.

The probability that a 2 digit number have different digits is 81/90.

This can reduce. Divide top and bottom by 9 giving 9/10.

Rewrite the function f(x)=16^x in four different ways, using a different base in each case.

Answers

Answer:

X=1

f(x)=16^1

=16

X=2

f(x)=16^2

256

X=3

f(x)=16^3

=4096

X=4

f(x)=16^4

=65536

Here are four different ways to rewrite the function f(x) = 16^x, using a different base for each case:

Using base 2:

f(x) = (2^4)^x = 2^(4x)

Using base 3:

f(x) = (3^2)^x = 3^(2x)

Using base 10:

f(x) = (10^(log10(16)))^x = 10^(log10(16) * x)

Using base e (natural logarithm):

f(x) = (e^(ln(16)))^x = e^(ln(16) * x)

How to explain the function

In these rewritten forms, the exponentiation of the base is expressed as a simpler expression.

This involves the new base, which helps to illustrate the relationship between the original function and the different bases used.

Learn more about functions

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Solve the system using substitution. x+y=-2 and x-y=-8

Answers

Answer:

1) x+y=-2

x=-2-y

2) x-y=-8

substitude value of x

(-2-y)-y=-8

-2-2y=-8

-2y=-6

y=3

Substitute value of y in 1

x=-2-3

x=-5

Brainliest please~

Find the length of BC
A. 6.81
B. 7.64
C. 13.37
D. 29.44

Answers

Answer:

13.37 = BC

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

cos theta = opp / hyp

cos 27 = BC / 15

15 cos 27 = BC

13.36509 = BC

Rounding to the nearest hundredth

13.37 = BC

Which of the following scatterplots do not show a clear relationship and would not have a trend line?

Answers

Answer:

the second one

Step-by-step explanation:

it is not going in any general direction

Answer:

B

Step-by-step explanation:

obtain the value of X for which (X+1),(X-5),(X-2) is a geometric progression.hence find the sum of the first 12 terms of the progression.​

Answers

If x + 1, x - 5, and x - 2 are in a geometric progression, then there is some constant r for which

x - 5 = r (x + 1)

==>   r = (x - 5) / (x + 1)

and

x - 2 = r (x - 5)

==>   r = (x - 2) / (x - 5)

Then

(x - 5) / (x + 1) = (x - 2) / (x - 5)

Solve for x :

(x - 5)² = (x - 2) (x + 1)

x ² - 10x + 25 = x ² - x - 2

-9x = -27

x = 3

It follows that the ratio between terms is

r = (3 - 5) / (3 + 1) = -2/4 = -1/2

Now, assuming x + 1 = 4 is the first term of the G.P., the n-th term a(n) is given by

a(n) = 4 (-1/2)ⁿ⁻¹

The sum of the first 12 terms - denoted here by S - is then

S = 4 (-1/2)⁰ + 4 (-1/2)¹ + 4 (-1/2)² + … + 4 (-1/2)¹¹

Solve for S :

S = 4 [(-1/2)⁰ + (-1/2)¹ + (-1/2)² + … + (-1/2)¹¹]

(-1/2) S = 4 [(-1/2)¹ + (-1/2)² + (-1/2)³ + … + (-1/2)¹²]

==>   S - (-1/2) S = 4 [(-1/2)⁰ - (-1/2)¹²]

==>   3/2 S = 4 (1 - 1/4096)

==>   S = 8/3 (1 - 1/4096)

==>   S = 1365/512

There is a rack of 15 billiard balls. Balls numbered 1 through 8 are solid-colored. Balsa numbered 9 through 15 contain stripes. If one ball is selected at random, determine the odds for it being striped.

Answers

If one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

What do we know?

We know that there are 15 billiard balls.

We also know that balls numbered 1 through 8 are solid-colored, so we have 8 solid-colored balls.

And the other 7 balls are striped.

Now we want to find the probability for a randomly selected ball to be a striped ball.

Because all the balls have the same probability of being randomly selected, the probability of randomly selecting a striped ball is equal to the quotient between the number of striped balls (7) and the total number of balls (15).

Then we have:

P = 7/15 = 0.467

That quotient is also what is called the "odds"

So if one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

If you want to learn more, you can read:

https://brainly.com/question/23044118

I need two examples of rounding to the thousandths place. SHOW ALL WORK!

Answers

Answer:

3.418

Step-by-step explanation:

3.4175

3.4178

u round if the number behind it is higher than 5

If\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\]where $a$ and $b$ are integers and $b$ is as small as possible, find $a+b.$

Answers

9514 1404 393

Answer:

  12

Step-by-step explanation:

Apparently, you want the sum a+b when ...

  [tex]\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\][/tex]

A calculator can show you the expression on the left evaluates to √243. In simplest terms, that is 9√3, so we have a=9, b=3 and ...

  a+b = 9+3 = 12

Answer:

12

Step-by-step explanation:

12,963 rounded to the nearest hundredth

Answers

9514 1404 393

Answer:

12,963.00 (in the US)12,96 (some other places)

Step-by-step explanation:

In the US, a decimal point is represented by a period. This value is interpreted as an integer with no fractional part, so the fractional part is zero:

 12,963.00

__

Some other places, a comma is used to identify the beginning of the decimal fraction. In that form, this number has a fractional part that has 3 as its thousandths digit. The value of 3 is less than 5, so the number is simply truncated at the hundredths place.

  12,96

If the thousandths digit were 5 or greater, then 1 hundredth would be added to the truncated number.

Donald has x twenty dollar bills and 1 yen dollar bill. How much money does Donald have?
Write your answer as an expression

Answers

Y=20x+1

I think, hope this helps!

A function of the form f(x)=ab^x is modified so that the b value remains the same but the a value is increased by 2. How do the domain and range of a new function compare to the domain and range of the original function?

Answers

Answer:

The domain and range remain the same.

Step-by-step explanation:

Hi there!

First, we must determine what increasing a by 2 really does to the exponential function.

In f(x)=ab^x, a represents the initial value (y-intercept) of the function while b represents the common ratio for each consecutive value of f(x).

Increasing a by 2 means moving the y-intercept of the function up by 2. If the original function contained the point (0,x), the new function would contain the point (0,x+2).

The domain remains the same; it is still the set of all real x-values. This is true for any exponential function, regardless of any transformations.

The range remains the same as well; for the original function, it would have been [tex]y\neq 0[/tex]. Because increasing a by 2 does not move the entire function up or down, the range remains the same.

I hope this helps!

Which inequality is shown in the graph?
I need help plz

Answers

Answer:

I am pretty sure it is B.

Step-by-step explanation:

This is a line with a positive slope, therefore we can discard c and d.

the sign < will mean that the shaded in area will be on your right side.

Yogi is 6 years older than Michelle. The sum of their ages is 26. Write a system of linear equations to represent this information. What are their ages?

Answers

Answer:

10 and 16, x+(x+6)=26

Step-by-step explanation:

Michelle has an age we don't know, so we put her age as x.

Yogi is 6 years older than her, so her age is x+6

Michelle=x

Yogi=x+6

we know both their ages equal 26. so we set it up as

x+(x+6)=26

combining like terms we get

2x+6=26

subtract 6 from both sides

2x=20

divide both sides by 2

x=10

now that we have the value for x, we plug it into their original ages

Michelle is 10, because her age is just x.

Yogi is 16, because her age is x+6

A tumor is injected with 0.3 grams of Iodine-125, which has a decay rate of 1.15% per day. To the nearest day, how long will it take for half of the Iodine-125 to decay?

Answers

Answer:

The time required is 60.3 days.

Step-by-step explanation:

initial amount, No = 0.3 g

rate, r = 1.15 % per day = 0.0115 per day

final amount, N = 0.15 g

Let the time is t.

[tex]N = No e^{-rt}\\\\0.15 = 0.3 e^{-0.0115 t}\\\\0.5 =e^{-0.0115 t}\\\\- 0.6931 = - 0.0115 t \\\\t = 60.3 days[/tex]

If the cost, C, for manufacturing x units of a certain product is given by c=x^2-5x+65, find the number of units manufactured at a cost of 13,865.

Answers

9514 1404 393

Answer:

  120

Step-by-step explanation:

I find it pretty easy to obtain the solution by graphing ...

  c(x) -13865 = 0

The positive value of x that makes this so is x = 120.

120 units will have a cost of 13,865 to manufacture.

__

If you like to solve this algebraically, you can probably do it most easily by completing the square.

  x^2 -5x = -65 +13865

  x^2 -5x +6.25 = 13806.25 . . . . . add the square of (-5/2)

  (x -2.5)² = 13806.25

  x -2.5 = √13806.25 = 117.5 . . . . only the positive square root is interesting

  x = 117.5 +2.5 = 120

Polynomial: 3x^4 + 5x - 4; Divisor: x - 1​

Answers

Answer:

3x³+3x²+3x+8+[tex]\frac{4}{x-1}[/tex]

Step-by-step explanation:

You can use synthetic division for this problem since the divisor is in (x-a) form. The fraction is the remainder over the divisor.

A machining center is in charge of producing 225 parts per day. The parts width. Any parts produced between 250mm and 260mm are considered gless than 250mm must be reworked at an additional cost of $8 per part. 260mm must be reworked at an additional cost of $2.50 per part. The varquantified as a standard deviation of 5.0mm. Measurements on these parhave the ability to set up the machine to achieve whatever mean width value you wish.

Required:
Setup a data table to determine the mean width setting that will minimize expected rework cost ($8 per small part and $2.50 per large part).

Answers

Answer: 5.0•2.50
Reason: it’s first grade level math
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