5. ∫(ABS((1/2·x^2 + 1) - (- x^2 + 3/2·x + 4)), x, -1, 2) = 6.75
6. ∫(ABS((x + 1) - (x^2 + 2·x - 1)), x, -2, 1) = 4.5
7. ∫(ABS((1/3·x^2 + 2/3·x) - (1/3·x^3 - 4/3·x)), x, -2, 3) = 253/36 = 7.028
8. ∫(ABS((1/2·x^2) - (1/2·x^3 + 1/2·x^2 - 2·x)), x, -3, 2) = 7.125