What is the solution to the system of equations?
3x-5y=7
2x+3y=30

a. (3 , -7)
b. (9 , 4)
c. (-3 , -7)
d. (3 , 7)

The correct answer is:

Yes.

Explanation:

When solving an equation, we are essentially working backward to cancel everything that's been done to the variable.

Since we are working backward, we start with the last thing done to the variable; this is the first thing we "undo."  Always start with whatever number is farther away from the variable and undo it first; undo by doing the opposite operation.

Continue this process until you have cancelled all numbers with the variable you're solving for.