The equation of a trapezoid is (a + b)/2 * h. So let's reverse the equation and divide the area by the height, 112/8 = 14. Now we should multiply it by 2, so we can get what a + b equaled. 28 = 11 + b
Start evaluating from the inside and work your way out. This means you start with (-3)²=9. Then go and plug that answer in to the equation f(x). f(9)=2(9)-1=17.
