Add and Subtract Rational Expressions with a Common Denominator · Exercise 38

If Pete can paint a wall in $p$ hours, then in one hour he can paint $\frac{1}{p}$ of the wall. It would take Penelope 3 hours longer than Pete to paint the wall, so in one hour she can paint $\frac{1}{p+3}$ of the wall. Add the rational expressions $\frac{1}{p}+\frac{1}{p+3}$ to get an expression for the part of the wall Pete and Penelope would paint in one hour if they worked together.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Elementary Algebra 2e · §8.3 Add and Subtract Rational Expressions with a Common Denominator · Exercise 38