Question

find zeros of x^2- 3 x + 2

Answer 1

x^2 - 3x +2 =0
x^2 -x - 2x +2 =0
x(x-1)-2(x-1)=0
(x-1)(x-2)=0
x=1,2
zeroes are 1,2

Answer 2

x²-3x+2
split the middle term
x²+-2x-x+2
common factors
x(x-2)-1(x-2)
(x-2)(x-1)
now,
x-2=0
x=2
and 
x-1=0
x=1
zeroes are 1 and 2