Please help it’s a math quiz!!

Simplify 15(x - 4)(x -1)-3(x + 4)(x - 1) with steps

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.