Consider the system. braceleftze 6x − 3y = 75 x + 3y = −12 Part 1 out of 2 Complete the description for three different substitution methods that can be used to solve this system. Solve the second equation for x (x = 9 − 3y) and then substitute the value into the first equation. Solve the first equation for y (y = 2x − 25 ) and then substitute that value into the second equation. Solve either equation for 3y (3y = -21 − x or 3y = 6x − 75 ) and then substitute that value into the other equation.