9x-2y=-21 2x+3y=16 Substitution

x = - 1 y = 6

Step-by-step explanation:

Solve equation [2] for the variable y

[2] 3y = - 2x + 16

[2] y = - 2x/3 + 16/3

Plug this in for variable y in equation [1]

[1] 9x - 2• (-2x/3+16/3) = - 21

[1] 31x/3 = - 31/3

[1] 31x = - 31

Solve equation [1] for the variable x

[1] 31x = - 31

[1] x = - 1

By now we know this much:

x = - 1

y = - 2x/3+16/3

Use the x value to solve for y

y = - (2/3) (-1) + 16/3 = 6

Solution:

{x, y} = {-1,6}