Verified answer

1) a² + 4a + 4 = a² + 2 * a * 2 + 2² = (a + 2)² = (a + 2)(a + 2)

2) 4x² - 25 = (2x)² - 5² = (2x - 5)(2x + 5)

3) 4m² - 12mn + 9n² = (2m)² - 2 * 2m * 3n + (3n)² = (2m - 3n)² =

= (2m - 3n)(2m - 3n)

Решение:

1)

a^2+4a+4=а^2+2*а*2+4=а^2+2*а*2+2^2=(а+2)^2

2)

4x^2-25=2^2*х^2-25=2^2*х^2-5^2=(2х)^2-5^2=(2х-5)(2х+5)

3)

4m^2- 12mn +9n^2=2^2*m^2-12mn+9n^2=2^2*m^2-2*2m*3n+9n^2=2^2*m^2-2*2m*3n+3^2*n^2=(2m)^2-2*2m*3n+3^2*n^2=(2m)^2-2*2m*3n+(3n)^2=(2m-3n)^2