Maximum value

First, we need to simplify $4(x + 7)(2 - x) + 4(x + 7)(8 - x)$into $−8x^2−16x+280$

The maximum value of any quadratic equation is $c - b^2/4a$, when the quadratic is in $ax^2 + bx + c$. By subsituting, we find that the maximum value for this equation is $\color{brown} 288$.