Find the sum of the polynomial functions. (Simplify you \[ \begin{aligned} P(x) & =2 x^{4}-2 x+5 \text { and } \\ R(x) & =5 x^{5}-5 x-7 \\ P(x)+R(x) & = \end{aligned} \] Show My Work (Optional)

Step 1 ：Given the polynomial functions P(x) = 2x^4 - 2x + 5 and R(x) = 5x^5 - 5x - 7

Step 2 ：To find the sum of the polynomial functions P(x) and R(x), we need to add the corresponding terms of the two polynomials. The corresponding terms are the terms that have the same degree.

Step 3 ：We add the coefficients of the corresponding terms to get the sum.

Step 4 ：The sum of the polynomial functions P(x) and R(x) is \(\boxed{5x^5 + 2x^4 - 7x - 2}\)