I have a function $$f(a,b,c,d,e)=(a+c)\exp\left(\frac{b}{d\cdot e}\right)\\a,b,c,d,e\in\mathbb{R}^+$$
I want to combine the two parameters $a, b$ into a single real parameter, so that I could plot values of $f$ for fixed values of $c,d,e$ and for given combinations of $a,b$. In other words, I would like to find functions $g, h$ such that $$f(a,b,c,d,e)=g(h(a,b),c,d,e)\\h(a,b)\in\mathbb{R}$$