Question

solve the system of equations 3y 2z = 12 and y – z = 9. a. y = 24, z = 15 b. y = 6, z = 15 c. y = 6, z = –3 d. y = –6, z = 15

Answer 1

If you would like to solve the system of equations 3y + 2z = 12 and y - z = 9, you can do this using the following steps:

3y + 2z = 12
y - z = 9 ... y = 9 + z
___________
3y + 2z = 12
3 * (9 + z) + 2z = 12
27 + 3z + 2z = 12
5z = 12 - 27
5z = -15
z = -15/5
z = -3

y = 9 + z = 9 - 3 = 6

The correct result would be c. y = 6, z = –3.