Question

The function for the cost of materials to make a shirt is f(x) = 5/6 x + 5, where x is the number of shirts. The function for the selling price of those shirts is g(f(x)), where g(x) = 5x + 6. Find the selling price of 18 shirts.

Answer 1

in case you'l like to find g( f(x) )
well, for example \(\bf f(x) = \color{blue}{\textit{whatever}} \qquad \qquad
g(x) = 2x^2 + 25x +1\\
g(f(x)) = 2(\color{blue}{\textit{whatever}})^2 + 25(\color{blue}{\textit{whatever}}) +1\)

every "x" variable gets replace in the "host function" by the "guest function"