1) (a+7)^2 2) b^2+10b+25 3) 25x^2-16 4) 9x^2-12xy+4y^2

Question

1) (a+7)^2 2) b^2+10b+25 3) 25x^2-16 4) 9x^2-12xy+4y^2

Answer 1

(а+7)² = а² + 2*а*7 +7² = а² + 14а + 49
b² + 10b  + 25  = b² + 2*b *5   + 5² = (b+5)²
25x² - 16  = (5x)²  - 4² = (5x-4)(5x+4)
9x²-12xy  + 4y² = (3x)² - 2*3x*2y  +(2y)² = (3x - 2y)²