112k views
5 votes
〔2x-3y=-8 〔9x+2y=-5 (5,6) (0,-4) (1,-7) (-2,1) Solution

User BigDaddy
by
8.3k points

1 Answer

7 votes

Answer:

Solution: x = -1; y = 2

Explanation:

Method to solve: Elimination:

Solving for x:

  • We can begin by multiplying first equation by 2 and the second equation by 3.

This will allow us to eliminate y when adding the equations since -6y + 6y = 0:

Multiplying 2x - 3y = 8 by 2:

2(2x - 3y = -8)

4x - 6y = -16

Multiplying 9x + 2y = -5 by 3:

3(9x + 2y = -5)

27x + 6y = -15

Now we can add the two equations to eliminate y and solve for x:

4x - 6y = -16

+

27x + 6y = -15

----------------------------------------------------------------------------------------------------------(4x + 27x) + (-6y + 6y) = (-16 - 15)

(31x = -31) / 31

x = -1

Thus, x = -1.

Solving for y:

Now we can solve for y by plugging in -1 for x in the first equation (2x - 3y = -8):

2(-1) - 3y = -8

(-2 - 3y = -8) + 2

(-3y = -6) / -3

y = 2

Thus, y = 2.

Checking the validity of the answers:

Now we can check that our answers are correct by plugging in -1 for x and 2 for y in both equations and seeing if we get the same answer on both sides of the equation:

Checking -1 for x and 2 for y in 2x - 3y = -8:

2(-1) - 3(2) = -8

-2 - 6 = -8

-8 = -8

Checking -1 for x and 2 for y in 9x + 2y = -5:

9(-1) + 2(2) = -5

-9 + 4 = -5

-5 = -5

Thus, our answer are correct.

User Iryna Prokopenko
by
8.5k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories