Answer
$A=102$
Work Step by Step
$y_1=3x^2+12$ $and$ $y_2=4x+4 $
$A= \int_{-3}^3 (y_1 - y_2)dx $
$A = \int_{-3}^{3} (3x^2+12-4x-4) dx $
$A= \int_{-3}^{3} (3x^2-4x+8)dx $
$A = [x^3-2x^2+8x]_{-3}^3 $
$A = [27-18+24]-[-27-18-24] $
$A = [33]-[-69] $
$A=33+69$
$A=102$