10
19 Solve the simultaneous equations.
You must show all your working.
x = 7 – 3y
x2 - y2 = 39

Answer:

11 if you mean x^2

Step-by-step explanation:

Since we are solving for x, we need to just get x by its self. The only thing we have to do is get rid of the exponent of (^2). to do this, we have to take teh square root of both sides:

The square root of x^2 is x

The square root of 121 is 11

So the asnwer is x = 11

Step-by-step explanation: A common mistake in this problem would be to say that if x² = 121, x must equal 11.

However, you must set the equation equal to 0 first.

So our first step is to subtract 121 from both sides to get x² - 121 = 0.

Next, factor the left side to get (x + 11)(x - 11) = 0

So either x + 11 = 0 or x - 11 = 0.

Solving each equation from here, we find that x = -11 or x = 11.

So our answer is not just 11, it's {11, -11}.

Answer:

Hey there!

Our equation can be: 2y+3=4y+2

Hope this helps :)

Answer:

2y+3=4y+2

I hope you got it..

Answer:

.75cm³

Step-by-step explanation:

To find the volume of a shape like this it is,

base×height×width.

In this case it is .5×.5×3=.75cm³

Answer:

3/4 or 0.75

Step-by-step explanation:

Length times width times height:

1/2 * 1/2 * 3

= 3/4

Answer:  Yes. The sales tax is 5% which equals $4.20 for $84

Step-by-step explanation:

[tex]\dfrac{0.60}{12}=0.05\qquad \rightarrow 5\%\\\\\\\dfrac{1.20}{24}=0.05\qquad \rightarrow 5\%\\\\\\\dfrac{1.80}{36}=0.05\qquad \rightarrow 5\%\\\\\\\dfrac{2.40}{48}=0.05\qquad \rightarrow 5\%[/tex]

The sales tax rate is proportional for the values in the table.

$84 x 0.05 = $4.20

The sales tax on a purchase of $84 is $4.20

Answer:

Step-by-step explanation:

y=x²+7

vertex(0,7)

the length of latus rectum in a parabola equal to four times the focal length :

y=x²+7

focus X=-b/2a=0

focus Y=c- (b²-1)/4a=7+1/4=29/4

focus (0 , 29/4)

latus rectum is 29/4

(x-h)^2 = 4p (y-k)   4p is the length of the latus rectum with vertex(0,7)

(0-0)²=4p(29/4-7)

0=29p-28p=1p

the length of the latus rectum is 1

Answer:

  1

Step-by-step explanation:

The short answer is that the length of the latus rectum is the reciprocal of the magnitude of the leading coefficient.

In y = x^2 +7, the leading coefficient is 1.

  latus rectum = 1/|1| = 1

Answer:

See step by step explantation

Step-by-step explanation:

Step 1. given

Step 2. Subtraction property of equality

Step 3. Simplification

Step 4. Subtraction property of equality

Step 5. Simplification

Step 6. Multiplication property of equality

Step 7. Simplification

Answer:

6200

Step-by-step explanation:

1 Dekagram = 1000 Centigram

6.2 x 1000 =

6200

Answer:

6200 centigrams

Step-by-step explanation:

deka means 10

centi means 100th

Answer:

22x -21

Step-by-step explanation:

(3x + 14) + (19x - 35)

Combine like terms

3x+19x   + 14-35

22x   -21

Answer:

67.02

Step-by-step explanation:

Answer:

2

Step-by-step explanation:

|-6+8|

Add/subtract the numbers: -6 + 8 = 2

= |2|

Apply the absolute value rule: |a| = a, a ≥ 0

= 2

Answer:

25/99; Dependent event

Step-by-step explanation:

This is the probability that an even ticket will be chosen out of 100 tickets times the probability that an odd ticket will be chosen out of the remaining 99 tickets.

There 50 even out of 100 to start off with. After 1 even is chosen there are still 50 odd but only 99 more tickets.

(50/100)(50/99)=2500/9900= 25/99

This is a dependent event because an odd number should come after the even number only.

Answer:

25/99

Dependent event

Step-by-step explanation:

1. Multiply the possibilities

There are 50 even numbers out of 100 numbers. If one even number is drawn and not replaced, that would leave the odd ticket to be drawn out of 99 tickets. Because an even number was drawn first, all 50 odd numbers would remain.

[tex]\frac{50}{100}[/tex] · [tex]\frac{50}{99}[/tex] = [tex]\frac{2500}{9900}[/tex]

Simplify

[tex]\frac{2500}{9900}[/tex] = [tex]\frac{25}{99}[/tex]

2. This is a dependent event because the chances of an odd number being drawn was altered. If the even ticket was replaced, the probability of the odd number being drawn would not have been affected.

Answer:

all real numbers

Step-by-step explanation:

f(x)=(1/3)^x

The domain is the values that x can take

X can take any value

Answer:

all real numbers

Step-by-step explanation:

Answer:

10,000

Step-by-step explanation:

Answer:

The answer is

Step-by-step explanation:

From the question difference in the statement means subtraction

So the statement

two times the difference of eight and d is written as

Hope this helps you

Answer:

the answer is 2( 8 - d) I  got the same answer and got it right

Step-by-step explanation:

Answer:  (i) 3

(ii) 10

(iii) 1080

Step-by-step explanation:

(i) Coefficient is the number written before any variable.

Coefficient of x in [tex]3x+10=36[/tex] is 3.

(ii) Constant is a numerical term written without any variable.

Constant in [tex]2x+10=5x[/tex] is 10.

(iii) Let x be the number of miles Katie's family drive.

Since they charge $30 combined with $0.25 per mile drive.

So, Total charge = 0.25 x +30 ( in dollars)

If they charged $300, then

[tex]0.25 x +30 =300[/tex]

Subtract 30 from both sides, we get

[tex]0.25x=270[/tex]

Divide both sides by 0.25, we get

[tex]x=1080[/tex]

Hence, Katie drove 1080 miles.

Answer:

pair3

Step-by-step explanation:

it is when they have same number of sides .

Answer:

1 and 3.

Step-by-step explanation:

Pair 1 and pair 3.

If we reposition one of them we see that it exactly fits onto the other.

Answer:

C. 10cm

Step-by-step explanation:

Bryce is making a model building.

He raises the walls of the building

by 2 centimeters five times. By how

many centimeters does Bryce raise

the walls all together?

(A) 2 cm

(C) 10 cm

(B) 5 cm

(D) 20 cm

Bryce raises the walls of the building 2centimeters five times

This means, he raises the walls 2centimeters five different times

By how many centimeters does Bryce raise the walls all together?

We can solve this by finding the product of 2centimeters five times

The total centimeters Bryce raises the walls altogether= 2 centimeters × 5 times

=2cm × 5

=10cm

Answer:

5 inches on the drawing = 32 actual inches

Step-by-step explanation:

195 inches

104 x 12 = 1248 inches

1/39

Answer:

she used a scale of 5 inches to represent 32 inches actual length

Step-by-step explanation:

We are told that helen made the gym to be 195 inches long in the drawing.

Now, we are told that the actual length of the gym is 104 ft long.

Thus, converting to inches,

1ft = 12 inches

So, 104ft = 104 × 12 = 1248 inches

Which means that 194 inches represented 1248 inches.

So the scale is:

195:1248

Dividing both by a common factor of 39 to give a scale of (195/39):(1248/39)

This gives;

5:32

So she used a scale of 5 inches to represent 32 inches actual length

Find the z-score for both 75% and 82% then subtract them.

Z-score for 75%:

75 -75 /7 = 0-7 = 0

Using empirical rule, This translates to a percentile if 50%

Z-score for 82%

82-75 /7 = 7/7 = 1

Using empirical rule, this translates to 84.13%

Answer = 84.13-50 = 34.13% round to 34%

Answer:

34%

Step-by-step explanation:

Well 75+7=82 and one hop on the graph is 34%.

Answer:

B

Step-by-step explanation:

The student's mistake was between Step 1 and Step 2.

Here, on the left side, they added 6x and 2x. The result should be 8x, not 4x.

It should be 8x-15=3x-75, not 4x-15=3x-75.

Answer:

1 day = 24 hours

we cam divide in 6 periods of 4 hours

if bacteria triples in size every four hours

3 millions at begining

3^7 = 2'187'000'000 bacteria

Espero que te sirva

Answer: Geometric progression

Step-by-step explanation:

0h -> 3x10^6 /4h-> 9x10^6 / 8h-27x10^6 / 12h->81x10^6 / 16h->243x10^6 / 20h-> 729x10^6 / 24h->2187x10^6 = 2.187.000.000.:

Answer:

She must jog 7 laps in order to meet her goal.

Step-by-step explanation:

A more accurate answer would be that she needs to run 6 1/4 laps to meet her goal. However, because the problem states that she will not be running partial laps, then the number of laps she runs must be a whole number, which in this case works out to be 7 laps.

Answer:

[tex]x =-5\ - \sqrt{8}[/tex]

Step-by-step explanation:

Given

[tex]x^2 + 10x + 25 = 8[/tex]

Required

Find the smallest value of x

[tex]x^2 + 10x + 25 = 8[/tex]

Expand the expression on the right hand side

[tex]x^2 + 5x + 5x + 25 = 8[/tex]

Factorize

[tex]x(x+5)+5(x+5) = 8[/tex]

[tex](x+5)(x+5) = 8[/tex]

[tex](x+5)^2 = 8[/tex]

Take Square root of both sides

[tex]\sqrt{(x+5)^2} = \±\sqrt{8}[/tex]

[tex](x+5) = \±\sqrt{8}[/tex]

Remove bracket

[tex]x+5 = \±\sqrt{8}[/tex]

Subtract 5 from both sides

[tex]x+5-5 =-5\± \sqrt{8}[/tex]

[tex]x =-5\± \sqrt{8}[/tex]

[tex]x =-5\ + \sqrt{8}[/tex] or [tex]x =-5\ - \sqrt{8}[/tex]

Comparing both values of x;

The smallest value of x is

[tex]x =-5\ - \sqrt{8}[/tex]

Answer:

Step-by-step explanation:

In this problem we are expected to calculate the fraction of a whole that belongs to a part. that is the fraction of the estate the belongs to American cancer society.

let us  state as given that the total estate is 5

and 4 is to be divided among relatives, remaining 1

out of the remaining 1 estate,

1/4 belongs to American cancer society

Therefore the fraction of the 5 estates that belongs to American cancer society is = 1/4 of 1/5= 1/9

To simplify use the distributive property first. Multiply 6 by each value inside the parentheses:

6(x-4) + 9

6x -24 + 9

Now combine like terms to get the final answer:

6x - 15

Answer:

C = 4 + 0.5d

Step-by-step explanation:

General equation: y = ax + b, with b is fixed term and a is rate per x.

Here,

C = y

fixed term b = 4

rate a = 0.5 per kilometer (d)

Answer:

32

Step-by-step explanation:

This is because you would want the feet and the radium kinda meeting up in a way and would need to make sure you can fill it in with th e drive way as it will be on a horizontal base so you would need X2 of the driveway to make it into a standing up horizontal base

Hope this helps

If this seems incorrect please comment with the answer that it should be and I shall change my answer thanks you :)

Answer:

The equal sign is generally placed at the separation between the left hand side and the right hand side

Step-by-step explanation:

Basically a typical equation has two parts, and one part is seen to be equal to the other part, and they are:

Generally equations are expressed algebraically,that is using letters/ alphabets and symbols to express mathematical relations

The left hand side mostly is the solution of the equation, while the right hand side contains symbols, alphabets used to find solution to the equation.

Answer:

30 billetes de 5 dólares y 15 billetes de 10 dólares

Step-by-step explanation:

I don't speak spanish but take it in school, so I understand the question but cannot respond back in spanish.

Letting x = $5 bills and y = $10 bills,

x + y = 45

5x + 10y = 300

Solving the system by substitution,

y = -x + 45

5x + 10(-x+45) = 300

5x - 10x + 450 = 300

-5x = -150

x = 30

Substituting the x-value back into the equation,

x + y = 45

30 + y = 45

y = 15

Checking my solutions, tells me that they are correct.

Hope this helped! If you don't understand the text, please us a translator!