Find two numbers that multiply to -30 (last term) and add to 7 (middle coefficient)
The two numbers are 10 and -3
10 times -3 = -30
10 plus -3 = 7
Using those two values gets us the two factors (y+10) and (y-3)
Therefore, y^2+7y-30 factors to (y+10)(y-3)
The equation y^2+7y-30 = (y+10)(y-3) is true for all values of y.
