Consider the system.

6x - 3y = 66
x + 3y = -10

Complete the description for three different substitution methods that can be used to solve this system.

Solve the second equation for x (x = - 3y) and then substitute the value into the first equation.
Solve the first equation for y (y = 2x - ) and then substitute that value into the second equation.
Solve either equation for 3y (3y = - x or 3y = 6x - ) and then substitute that value into the other equation.