Question

How can you factorize `x^2 + 4x -4` ?

I found `(x+2+2sqrt2)(x+2-2sqrt2)` by using delta but isn't there sth better? Thanks

Answer 1

use the quadratic formula

Explanation:

substitute: a=1
b=4
c=-4

Answer 2

`(x+2+2sqrt2)(x+2-2sqrt2)`

Explanation:

`"to factorise find the roots using the "color(blue)"quadratic formula"`

`"given a quadratic in standard form ";ax^2+bx+c=0`

`"then the roots can be found using the quadratic formula"`

`•color(white)(x)x=(-b+-sqrt(b^2-4ac))/(2a)`

`x^2+4x-4=0" is in standard form"`

`"with "a=1,b=4" and "c=-4`

`rArrx=(-4+-sqrt(16+16))/2=(-4+-sqrt32)/2=(-4+-4sqrt2)/2`

`rArrx=-2+-2sqrt2larrcolor(blue)"roots(zeros)"`

`rArr(x-(-2-2sqrt2))(x-(-2+2sqrt2))" factors"`

`rArrx^2+4x-4=(x+2-2sqrt2)(x+2-2sqrt2)`