Explanation: Translate the problem into an equation: x 2 = x + 12 Solve the quadratic equation: x 2 − x − 12 = 0 Try factoring. If this does not work, we can use the quadratic formula: ( x + 3 ) ( x − 4 ) = 0 x = − 3 or x = 4 Throw out the negative result: x = 4
