Math
posted by Jake .
Use the functions f(x)=x+4 and g(x)=2x5 to find the specified functions.
(g x f)^1

Please state in words your notation
(g x f)^1 I assume you do not mean the reciprocal of g times f. 
let y = g x f
= (x+4)(2x5)
y = 2x^2 + 3x  20
so the inverse of that is
x = 2y^2 + 3y  20
2y^2 + 3y  20  x = 0
which by the way is not a function
to solve for y you will have to use the quadratic formula and
y = (3 ± √(98(20x))/4
etc.