We can combine the two integrals into a single integral since they have the same limits of integration:
∫−21(x2+2x+7)dx+∫−21(x2−2x−5)dx=∫−21[(x2+2x+7)+(x2−2x−5)]dx =∫−21(2x2+2)dx Now, we find the antiderivative of 2x2+2: ∫(2x2+2)dx=32x3+2x+C. Next, we evaluate the definite integral using the Fundamental Theorem of Calculus:
∫−21(2x2+2)dx=[32x3+2x]−21=(32(1)3+2(1))−(32(−2)3+2(−2)) =(32+2)−(32(−8)−4)=32+2−(−316−4)=32+2+316+4=318+6=6+6=12.