7. (24 points) Calculate the following indefinite and definite integrals. State the substitution and show all your work while computing the integrals. a) S8x + x3 dx= b) Sxe 9x2-2 dx= c) 2(6x2 - 8x) dx = d) Sa sec2 (t) dt = e) Sasin' (t) cos (t) dt = f) S vx + 3 dx= 1 g) .3 Je x ( In(x) )2 dx=