Question

X^2 - 4x + 3 how do I factor the expression completely

Answer 1

Bx must be the sum of the numbers in the bracket and c must be the product. So we need to choose 2 numbers that multiply to make 3 and add to make -4.

A negative x negative = positive so
-3*-1=3
-3-1=-4

Therefore:
(x-3)(x-1)

Answer 2

$x^2 - 4x + 3=\\ x^2-x-3x+3=\\ x(x-1)-3(x-1)=\\ (x-3)(x-1)$