x² + 4x + 4 = 0
Find two numbers whose poduct gives 4 and sum gives 4
Replace the coefficient of x by the number
That is;
x² + 2x + 2x + 4 = 0
x(x+2) + 2(x+ 2) = 0
x+ 2 = 0
x = -2 twice
It has one solution
x² - 2x + 1 = 0
x² -x - x + 1 = 0
x(x - 1) - 1(x - 1) = 0
(x-1)(x-1) = 0
x = 1
It has one solution
x² + 6x + 5 = 0
x² + 5x + x + 5 = 0
x(x + 5) + 1 (x+ 5)
(x+5)(x+1) = 0
Either
x+5=0 or (x+1)=0
x = -5 or x = -1
It has two solutions
