so finverse(8)=? means that f(?)=8 that might not make sense to you but I know that
what that means is we just need to solve the equation 8=(x+5)/(x+10) so multiply both sides by x+10 8(x+10)=x+5 8x+80=x+5 minus x both sides 7x+80=5 minus 80 both sides 7x=-75 divide both sides by 7 x=-75/7
