What is the maximum value of 4(x + 7)(2 + x) , over all real numbers x?
Did you mean (2-x)? If you did, then the max is 81 at x=-5/2.
4 ( x+7)(x+2) expand
4 ( x^2 +9x + 14)
4x^2 + 36x + 56 is a bowl shaped parabola max value = + infinity
MIN value occurs at - b/ 2a = - 36/8 = - 4.5 use this value of 'x' in the equation to calculate the min value