Answer:
(p-r)÷(p+r)
Step-by-step explanation:
p²-pr-pq+qr÷p²+pr-pq-qr
= p(p-r)-q(p-r) ÷ p(p+r)-q(p+r)
= (p-q)(p-r)÷ (p-q)(p+r)
= (p-r)÷(p+r)
