Answer:
[tex]\large\boxed{q=\dfrac{1-pr}{p}}[/tex]
Step-by-step explanation:
[tex]p(q+r)=1\qquad\text{use the distributive property}\\\\pq+pr=1\qquad\text{subtract}\ pr\ \text{from both sides}\\\\pq=1-pr\qquad\text{divide both sides by}\ p\neq0\\\\q=\dfrac{1-pr}{p}[/tex]
