How do you factor x^2+4x+4?

1 Answer
May 4, 2015

Factoring by color(blue)(GROUPING) :

x^2 + 4x+ 4 in general form is ax^2 + bx + c :

here:
color(red)(a) = 1 (coefficient of x^2)
color(red)(b) = 4(coefficient of x)
color(red)(c) = 4 (constant term)

now: a . c = 4 (product of first and last term of the equation)

now, we need to find two factors of a.c which need to add up to the middle term (which is b )

a.c = 4.1
a.c = 2.2 , here , 2+2 adds up to 4:

so we can factor as follows:
x^2 + 4x+ 4 = x^2 + 2x + 2x + 4 (splitting middle term)

= x(x+2) + 2(x +2) ( taking out common terms )
= (x+2)(x+2)