Evaluate the expression: x + x2 - 56

Step 1: Factor the quadratic equation.

$x^2 - 7x + 12 = 0$

Find two numbers that multiply to 12 and add to -7: -3 and -4.

$x^2 - 7x + 12 = (x - 3)(x - 4) = 0$

Step 2: Set each factor equal to zero.

$x - 3 = 0 \quad \Rightarrow \quad x = 3$

$x - 4 = 0 \quad \Rightarrow \quad x = 4$

The roots are $x = 3$ and $x = 4$.

x=3,\ 4