Question

inverse of f(x)= 2x-5??

Answer 1

y = 2x - 5
x = 2y - 5
x + 5 = 2y
y = (x+5)/2
f^-(x) = (x+5)/2

Answer 2

think of f(x) as y
so y = 2x-5
now solve for x in terms of y:
2x = y+5
x = (y+5)/2