Special cases of factoring

Question

A square picture frame has an area of 4x2 + 20x + 25 cm 2. What polynomial can represent the length of its side? Justify your answer

Answer 1

4x^2 +20x + 25

(2x+5) (2x+5) ---> When factored.

2x + 5 =0 2x + 5 =0

-5 -5 -5 -5

__________ _________

2x =-5 2x = -5

___ __ ___ ___

2 2 2 2

X-=5/2 X= 5/2