Question

Solve the system 3x - 2y = -8, 5x + 3y = -7 by the substitution method. The y-value of the solution is:

Answer 1

A) 3x - 2y = -8
B) 5x + 3y = -7

Solving equation A
3x = 2y -8
x = (2/3)y -(8/3)

Substituting this into equation B

5x + 3y = -7
5* [(2/3)y -(8/3)] + 3y = -7
10/3 y -40/3 + 3y = -7

6(1/3)y -(40/3) = -7

19y -40 = -21

19y = 19

y = 1