To solve for y you have to get y by itself. To do that, you use inverse operations. The inverse of addition is subtraction and inverse of multiplication is division.
-4x - 10 = -2y Divide by -2 to get y alone. What you do to one side of the
÷-2 ÷-2 equation, you must do to the other.
-2x - 5 = y
So the answer is b, y=-2x-5