Question

Which is equivalent to (−2m + 5n)², and what type of special product is it?
A. 4m² + 25n²; a perfect square trinomial
B. 4m² + 25n²; the difference of squares
C. 4m² − 20mn + 25n²; a perfect square trinomial
D. 4m² − 20mn + 25n²; the difference of squares

Answer 1

(-2m + 5n)²

(-2m + 5n) (-2m + 5n)
-2m(-2m + 5n) + 5n(-2m + 5n)

4m² - 10mn - 10mn + 25n²
4m² - 20mn + 25n²

4m²⇒ -2m * -2m
-20mn ⇒ 2(-2m)(5n)
25n² ⇒ 5n * 5n

C. 4m² − 20mn + 25n²; a perfect square trinomial