Question

select the expression that is equivalent to x^2-4

A.(x-2)^2

B.(x-2)(x+2)

C.x^2+2x+4

D.x^2-2x,4

Answer 1

$x^2-4=x^2-2^2=(x-2)(x+2)\\\\Use\\\\(a-b)(a+b)=a^2-b^2\\\\Answer:\ \boxed{B.\ (x-2)(x+2)}$