Question

What are the zeroes of f(x) = x2 - 6x + 8? (4 points) x = -4, 2 x = -4, -2 x = 4, 2 x = 4, -2

Answer 1

$f(x)=x^2-6x+8\\\\the\ zeros:f(x)=0\to x^2-6x+8=0\\\\x^2\underbrace{-4x-2x}_{=-6x}+8=0\\\\x\cdot x-x\cdot4-2\cdot x-2\cdot(-4)=0\\\\x(x-4)-2(x-4)=0\\\\(x-4)(x-2)=0\iff x-4=0\ or\ x-2=0\\\\therefore\\\\\boxed{x=4\ or\ x=2}$