A = 36 − 25x²
= 6² − (5x)²
= (6 + 5x) 6 − 5x)
B = 100 + 60x + 9x²
= 10² + 2(10)(3x) + (3x)²
= (10 + 3x)²
C = 2i (i+1) + 2i (2+i)
= 2i (i + 1 + 2 + i)
= 2i (2i + 3)
D = b² − 10b + 25
= (b)² − 2(b)(5) + (5)²
= (b − 5)²
E = (2 − x)² + (2 − x) (9 + x)
= (2− x) (2 − x) + (2 − x) (9 + x)
= (2 − x) (2 − x + 9 + x)
= (2 − x) (11)
F = (5x + 1)² − 81
= (5x + 1)² − 9²
= (5x + 1 + 9) (5x + 1 − 9)
= (5x + 10) (5x − 8)
G = (7d + 2)² − (3d + 4)²
= [ (7d + 2) + (3d + 4) ] [ (7d + 2) − (3d + 4) ]
= (10d + 6) (4d − 2)
