What is the solution to the above system of equations?

2x+5y=-4

4x-5y=22

A. (3,-2)

B. (13/3, - 24/3)

C. (-2,3)

D. (3,2/5)

Answer: A. (3,-2)

Step-by-step explanation:

Solve by Substitution:

/ / Solve equation [2] for the variable x

[2] 4x = 5y + 22

[2] x = 5y/4 + 11/2

/ / Plug this in for variable x in equation [1]

[1] 2• (5y/4+11/2) + 5y = - 4

[1] 15y/2 = - 15

[1] 15y = - 30

/ / Solve equation [1] for the variable y

[1] 15y = - 30

[1] y = - 2

/ / By now we know this much:

x = 5y/4+11/2

y = - 2

/ / Use the y value to solve for x

x = (5/4) (-2) + 11/2 = 3

Solution:

{x, y} = {3,-2}

1. B: (2,3) 2. C:4 3. B: (shaded on the right) 4. A: (x+y=7 6.50x+3.50y=33.50) 5. C: (3 quarters shaded at the top) 6. A:-4 7. C:6lbs (gc) 2lbs (jb) 5lbs (hc) 8. C:one solution 9. C:4x-7y=-12 - 14x+4y=4 10. A: (3,-2)