3a + 7 b = 2
2a + 9 b = 15

solve this linear equations using elimination method

please show your working ✨✨ THANK YOU

Answers

Answer 1

Answer:

a = -87/13

b = 41/13

Step-by-step explanation:

3a + 7b = 2

2a + 9b = 15

You need to have one of the coefficients have the same number but the opposite sign in both equations.  Multiply the first equation by -2 and the second equation by 3.  You will then be able to cancel out a and solve for b.

-2(3a + 7b) = -2(2)

-6a - 14b = -4

3(2a + 9b) = 3(15)

6a + 27b = 45

-6a - 14b = -4

6a + 27b = 45

0a + 13b = 41

13b = 41

b = 41/13

Plug in the b-value into one of the given equations and solve for a.

3a + 7b = 2

3a + 7(41/13) = 2

3a + 287/13 = 2

3a = -261/13

a = -87/13


Related Questions

2√63 what is the radical

Answers

Answer:

7.94

Step-by-step explanation:

Answer:

[tex]\Large \boxed{\sqrt{63}}[/tex]

Step-by-step explanation:

A radical is the root of a number.

[tex]2\sqrt{63}[/tex]

The radical in this expression is [tex]\sqrt{63}[/tex].

Negative solution for Multi-step equations

Answers

Answer:

[tex]\frac{1}{2}(4x+6)+3x=7x+9[/tex]

[tex]\frac{1}{2}(4x+8)+3x=7x+9[/tex]

Step-by-step explanation:

By putting the numbers in the given equation,

[tex]\frac{1}{2}(4x+6)+3x=7x+9[/tex]

2x + 3 + 3x = 7x + 9

5x + 3 = 7x + 9

(5x + 3) - 7x = (7x + 9) - 7x

(5x - 7x) + 3 = 9

-2x + 3 = 9

(-2x + 3) - 3 = 9 - 3

-2x = 6

[tex]-\frac{2x}{2}=\frac{6}{2}[/tex]

-x = 3

x = -3

Therefore, our equation is correct which has a negative result.

In place of 6 if we use 8, value of x will be negative again.

Please is urgent!!! ​

Answers

Answer:

70.6x 10-⁵ is answer of first

I need help on this can someone help

Answers

Answer:

1:3

Step-by-step explanation:

[tex]3:9\\= 1: 3[/tex]

Answer:

1   : 3

Step-by-step explanation:

pears : apples

3           9

Divide each side by 3

3/3      9/3

1   : 3

I NEED HELP I GIVE 5 STARS PLEASE ;(

Answers

the answer is 2 3/7

Which expressions are equivalent to 2(4f+2g)2(4f+2g)2, left parenthesis, 4, f, plus, 2, g, right parenthesis ? Choose 3 answers: Choose 3 answers: (Choice A, Checked) A 8f+2g8f+2g8, f, plus, 2, g (Choice B) B 2f(4 + 2g)2f(4+2g)2, f, left parenthesis, 4, plus, 2, g, right parenthesis (Choice C) C 8f+4g8f+4g8, f, plus, 4, g (Choice D, Checked) D 4(2f+g)4(2f+g)4, left parenthesis, 2, f, plus, g, right parenthesis (Choice E) E 4f+4f+4g4f+4f+4g

Answers

Answer:

8f + 4g

Step-by-step explanation:

Given

2(4f + 2g)

Required

Determine the equivalent expression

2(4f + 2g)

Open the bracket

2 * 4f + 2 * 2g

Perform right operations on the above

8f + 4g

The expression cannot be further simplified; Hence the result of  2(4f + 2g) when simplified is 8f + 4g

Answer: 8f + 4g also 4(2f + g) and 4f + 4f+ 4g

Step-by-step explanation:

Please answer quickly! A radio telescope has a parabolic surface, as shown below. A parabola opening up with vertex at the origin is graphed on the coordinate plane. The height of the parabola from top to bottom is 1 meter and its width from left to right is 20 meters. If the telescope is 1 m deep and 20 m wide, how far is the focus from the vertex?

Answers

Answer:

Basing on the description, a parabola checking with vertex at origin, the formula with vertex at origin can be used, x^2 = 4py. p is the focus therefore with the dimensions given, we get yourself a 0.25 and this is the distance of the focus to the vertex.

What is the measure of angle X?

Answers

Answer: 71 degrees

====================================================

Explanation:

Focus on triangle BDH

Interior angles B and D are given to be 40 and 31 respectively. Interior angle H is unknown

For any triangle, the interior angles always add to 180

B+D+H = 180

40+31+H = 180

H+71 = 180

H = 180-71

H = 109

Interior angle H is 109 degrees for triangle BDH

The exterior angle is 180 minus this measure

exterior angle = 180 - (interior angle)

exterior angle = 180 - 109

exterior angle = 71

Note how this is the sum of interior angles B and D, so you could use the remote interior angle theorem here.

divide the sum of -5,-10 and -9 by the product of 2 and -3

Answers

Answer: 1/4

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

=(-5)+(-10)+(-9)/2*(-3)

=-5-10-9/-6

=-24/-6

=4 ans.....

I need help on this :(

Answers

Answer:

26⁹

Step-by-step explanation:

26 * 26⁸

= 26¹ * 26⁸

= 26¹⁺⁸

= 26⁹

Find the coordinates of the midpoint of the segment given its endpoints.
3. A (5, 8 ) and B(-1,-4)​

Answers

Answer:

(2, 2 )

Step-by-step explanation:

Given endpoints (x₁, y₁ ) and (x₂, y₂ ) then the midpoint is

[ [tex]\frac{1}{2}[/tex] (x₁ + x₂ ) , [tex]\frac{1}{2}[/tex] (y₁ + y₂ ) ]

Here (x₁, y₁ ) = (A(5, 8) and (x₂, y₂ ) = B(- 1, - 4) , thus

midpoint = [ [tex]\frac{1}{2}[/tex] (5 - 1), [tex]\frac{1}{2}[/tex] (8 - 4 ) ] = (2, 2 )

How to do this question plz answer my question step by step plzz plz plz plz plz ​

Answers

I hope this helps you!

Please answer the question in the image below ASAP

Answers

Answer:

Option A Center: 2,-3 radius =5

Step-by-step explanation:

[tex](x-h) ^2+(y-k) ^2 =r^2[/tex]

The above equation is the general standard equation for the circle centered at (h,k) with radius r

Given that the equation of the circle is

[tex](x-2) ^2+(y+3) ^2 =25[/tex]

Comparing this with the general equation we can get the center and the radius as

[tex](x-h) ^2+(y-k) ^2 =r^2\\(x-(2)) ^2+(y-(-3)) ^2 =5^2[/tex]

We can now see that

h= 2

k= -3 and

r= 5

In ΔABC, and m∠ABC = 90°. D and E are the midpoints of and , respectively. If the length of is 9 units, the length of is units and m∠CAB is °.

Answers

Applying the midsegment theorem and the definition of isosceles triangle:

DE = 4.5 units

m∠CAB = 45°

The image that shows ΔABC is attached below.

Since AB = BC, therefore, ΔABC is an isosceles triangle.

This implies that, the base angles will be equal.

Thus:

If m∠ABC = 90°, therefore,

m∠CAB = ½(180 - 90)

m∠CAB = 45°.

DE is the midsegment of the triangle, and is parallel to the third side, CA = 9 units.

Based on the midsegment theorem, we have the following equation:

DE = ½(9)

DE = 4.5 units.

Therefore, applying the midsegment theorem and the definition of isosceles triangle:

DE = 4.5 units

m∠CAB = 45°

Learn more about midsegment theorem on:

https://brainly.com/question/7423948

Answer:

4.5
45

Step-by-step explanation:

Thirteen people on a sports team show up for a game. a. How many ways are there to choose 10 players to play the game? b. How many ways are there to assign the 10 different positions by selecting players from the 13 who show up?

Answers

Answer:

a)286 ways

b)1,037,836,800 ways

Step-by-step explanation:

a. How many ways are there to choose 10 players to play the game?

We have to take note of a key word here which is CHOOSE. For question a, order does not matter.

Hence, we use the combination formula. This is given as:

C(n, r) = nCr = n!/r! (n - r)!

n = 13, r = 10

13C10 = 13!/10! (13 - 10)!

= 13!/ 10! × (3!)

= 13 × 12 × 11 × 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 / (10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1) × (3 × 2 × 1)

= 1716/6

= 286 ways.

b. How many ways are there to assign the 10 different positions by selecting players from the 13 who show up?

For question b as well, we take note of a key word which is ASSIGN. For question b, order is very important.

Therefore, the formula we use is the permutation formula.

P(n, r) = nPr = n!/(n - r)!

n = 13, r = 10

13P10 = 13!/ (13 - 10)!

= 13!/ 3!

= 13 × 12 × 11 × 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 / (3 × 2 × 1)

= 1,037,836,800 ways

How many positive even factors of 48 are greater than 24 and less than 48

Answers

Answer: 0

Work Shown:

Factors of 48 = {1, 2, 3, 4, 6, 8, 12, 16, 24, 48}

Erase the odd numbers of that list to get {2, 4, 6, 8, 12, 16, 24, 48}

Then highlight stuff that is greater than 24, and less than 48 at the same time.

No factors fit this description since 24 cannot be larger than itself, and 48 cannot be smaller than itself.

Answer: 0

Step-by-step explanation:

There is no number greater than 24 and less than 48.

helppppppp please I beg ​

Answers

Answer:2/6, 7/21, 15/45

Step-by-step explanation:

So we know that 6,21,45 are all multiples of 3

To find the numerator we have to divide each multiple by 3

so for the first one it would be 6/3 which is 2. So 2 is the numerator and the answer for the first one is 2/6

now we have to do the same method for the next fraction so we do 21/3=7

so the numerator is 7 and the fraction is 7/21

now for the last one we have to do the same method again

45/3=15 so the numerator is 15 and the answer is 15/45

You can use this method for any question like this

so the final answers are 1/3=2/6=7/21=15/45

Hope this helps

3x2 − y3 − y3 − z if x = 3, y = −2, and z = −5.

Answers

Answer:

35

Step-by-step explanation:

3x2=6

or if x is variable :18

2x3=6

2x3=6

+5

add them all up:

18+6+6+5=35

let me know if something is confusing.

A paintball court charges an initial entrance fee plus a
fixed price per ball.
P represents the total price (in dollars) as a function of
the number of balls used n.
P=0.80n + 5.50
What is the price for 10 balls, not including the
entrance fee?
$....

Answers

Answer:

$8

Step-by-step explanation:

Firstly, Let us identify the variables in the functions.

The function states that for every n ball, the price is $0.80. Plus the $5.50.

Now that we know what the function stands for, we can substitute 10 into n, and remove the entrance fee of $5.50.

P=0.80n

This gives us $8, which means the price for 10 balls not including the entrance fee is $8.

A boom seller sold 50 books for $ 890.00 and earned a profit of $ 90.00. Find the cost price of 50 books.​

Answers

Answer:

$ 800

Step-by-step explanation:

number of books sold = 50

money earned = $ 890.00

profit = $ 90.00

Then the price of 50 books will be (money earned) - (profit)

= 890 - 90

= 800

So, the cost of 50 books is $ 800

HOPE IT HELPS :)

PLEASE MARK IT THE BRAINLIEST!

Can you help me please.

Answers

Answer:

option 2.

Step-by-step explanation:

You use the y-intercept form: y=mx+b

mx=slope, and b=y-intercept.

Looking at this graph, you can see that the slope is -2/3 (rise over run), and the line is negative, so the slope becomes negative.

So now, we can see the only option having the slop -2/3x is option 2.

Can someone pls help me &THANK YOU



SLATTTT!!!

Answers

BABYYYY SOSAAAAA CASH CARTIIII

One hundred people, ages 11-15, were randomly surveyed to find their opinion of their favorite leisure time activity. Sixty-four percent of them said they liked to spend time watching TV. If there are 1500 students in your school, about how many of them would you predict would enjoy watching t.v. A.2343 B.960 C.640 D.500

Answers

Answer:

If there are 1500 students in your school then 960 students would enjoy watching TV

Step-by-step explanation:

Step 1: We know that 64% of kids aged from 11 to 15 enjoy watching TV and there is 1500 students in your school

Step 2: We now want to find 64% of 1500, we can rewrite 64% as 0.64. We multiple 1500 by 0.64 to find out how many students enjoy watching TV

0.64 x 1500 = # of students who like watching TV

960 = # of students who like watching TV

Therefore out of 1500 students, 960 would enjoy watching TV

Here is a rule to make a list of numbers: Each number is 4 less than 3 times the previous number. Start with 10, build a sequence of 5 numbers.

Answers

Answer:

10,26,74,218,650

Explanation:

Each number is 4 less then 3 times than previous number.

The list of number is bounded by a set of rules that guide the creation of the set of numbers. The first 5 terms are: 10, 26, 74, 218, 650

Represent the number of terms with n.

So, the nth term is: [tex]T_n[/tex]

The start of the build is 10 means:

[tex]T_1 = 10[/tex]

The rule to generate the next terms is:

[tex]T_{n+1} = 3 \times T_n - 4[/tex] ---- i.e. 4 less than 3 times the previous term

So, the next terms till the 5th are:

[tex]T_{2} = 3 \times 10 - 4 = 26[/tex]

[tex]T_{3} = 3 \times 26- 4 = 74[/tex]

[tex]T_{4} = 3 \times 74- 4 = 218[/tex]

[tex]T_{5} = 3 \times 218- 4 = 650[/tex]

So, the first 5 terms are: 10, 26, 74, 218, 650

Read more about patterns at:

https://brainly.com/question/13382968

Identify whether each phrase is an expression, equation, or inequality.
Term
Phrase
Expression
3 - 53 =y
Inequality
7-5 <2.9
2 + 0
Equation
24"
t

Answers

Answer:

The identities of the terms are;

3 - 53 = y is an equation

7.5 < 2.9 is an inequality

2 + 0 is an expression

t is a term

24" is a term

Step-by-step explanation:

An equation is an expression with the equal to sign

3 - 53 = y is an equation

An inequality is a mathematical expression that contains an inequality sign

7.5 < 2.9 is an inequality

A term is a sole number or variable or the product of variables and numbers that come before and after mathematical operators such as +, ×, -, or ÷

t and 24" are terms.

Please help!!! ***This is multiple choice!

Answers

Answer:

0.6

Step-by-step explanation:

A probability is the likelihood of an event occurring. A probability function is a function in which at any point, its probability value can be estimated. The integral of the probability function is always ≤ 1

To find the probability that x = 2 or 3, we simply add their respective individual probabilities, therefore:

P(X = 2 or 3) = P(X = 2) + P(X = 3) = P(2) + P(3) = 0.5 + 0.1 = 0.6.

P(X = 2 or 3) = 6

A boy weighing blank kilograms is riding a skateboard. He’s moving at 2 meters/second and has 40 joules of kinetic energy. He doubles his speed when he sees his friends ahead of him. His kinetic energy at the faster speed is blank joules.

Answers

Answer:

His kinetic energy at the faster speed is 160 J

Step-by-step explanation:

Here in this question, we are interested in calculating the kinetic energy at the faster speed.

Firstly, we need to know the mass of the boy’s body. We can do this by using the kinetic energy formula;

Mathematically;

K.E = 1/2 * m * v^2

From the question;

K.E = 40 Joules

m = ?

v = speed = 2 m/s

Now, plugging these values into the kinetic energy equation, we have;

40 = 1/2 * m * 2^2

40 = 1/2 * m * 4

40 = 4m/2

4m = 40 * 2

4m = 80

m = 80/4

m = 20 kg

Now that we know the mass of the boy’s body, we can proceed to calculate the new K.E

Let’s follow the third statement in the question;

We were told that he doubles his speed upon sighting his friend.

Recall, he was traveling at a speed of 2 m/s.

Now doubling this means the new speed will

be 2 * 2 = 4 m/s

Now, we want to calculate the kinetic energy value at this new speed.

Mathematically, we use the same formula for kinetic energy.

K.E = 1/2 * m * v^2

We know that m is the mass that we calculated as 20kg and our v here is 4 m/s

Plugging these values, we have;

K.E = 1/2 * 20 * 4^2

K.E = (20 * 16)/2

K.E = 320/2

K.E = 160 J

Answer:

A boy weighing 20 kilograms is riding a skateboard. He’s moving at 2 meters/second and has 40 joules of kinetic energy. He doubles his speed when he sees his friends ahead of him. His kinetic energy at the faster speed is 160 joules.

I need help and I will give five stars and a big thank you comrades

Answers

Answer:

A.

Step-by-step explanation:

A way to find the equation of the graph is to find the solutions.

On the graph, the solutions are where the function intersects the x-axis. That would be where x = -2, x = 1, and x = 3.

In the equations, you will need to find factors when the x is inputted, the factor equals 0. For example, one of the factors is (x + 2). This is because x + 2 = 0, so x = 0 - 2, so x = -2. So, the three factors are (x + 2), (x - 1), and (x - 3).

The correct equation is A.

Hope this helps!

Factor completely 3x^2 - x - 4

A.(3x - 4)(x + 1)

B.(3x + 4)(x - 1)

C.(3x - 2)(x + 2)

D.(3x - 1)(x + 4)

Answers

Answer:

B. [tex](3x-4)(x+1)[/tex]

Step-by-step explanation:

Susan wants to buy cherries for a party. She has $8.00 to spend. Cherries are $2.75/kg. How many kilograms of cherries can Susan buy? Round to the nearest tenth. Use complete sentences to describe how you would solve this question. Be sure to explain how you round the answer.

Answers

Answer: you would have to divide $8.00/$2.75 and it would equal $2.90

Step-by-step explanation: This may help and if it does please thank me in the comments.

Answer:

Susan can purchase 2.9 kg of cherries.

Step-by-step explanation:

We need to take the amount of money available and divide by the cost of cherries per kilogram

$8.00 / $2.75  per kg

2.909090909 kg

Rounding to the nearest tenth, the solution is 2.9 kg

Susan can purchase 2.9 kg of cherries.

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