F(g(x)) = [(-7x-8)/(x-1) - 8} / [(-7x - 8)/(x-1) + 7] =
[(-7x - 8 - 8(x-1)) / (x-1)] / [(-7x - 8 + 7(x-1)) / (x-1)] = (-15x) / (-15) = x.
g(f(x)) = [-7*(x-8)/(x+7) - 8] / [(x-8)/(x+7) - 1] =
[(-7x + 56 -8*(x+7)) / (x+7)] / [(x - 8 - (x + 7)) / (x+7)] = (-15x) / (-15) = x.
So since f(g(x)) = g(f(x)) = x we can conclude that f and g are inverses.
Okay so you are correct with the gradient of the perpendicular line it is -5/2 however the equation is not y= -5/2 -1 because it is a new Line and has a new y-intercept therefore its Y=-5/2 + C but you have corrected that when doing the formula and have got the right answer
1) Area of trapezoid =1/2(base 1 +base 2)* height