Answer:
(1 + x)(p - q)
Explanation:
Given
p - q - x(q - p) ← distribute parenthesis by - x
= p - q - qx + px ← rearrange terms in p and terms in q
= p + px - q - qx ( factor first/second terms and third/fourth terms )
= p(1 + x) - q(1 + x) ← factor out (1 + x) from each term
= (1 + x)(p - q)