Question

multiply and simplify completely: (x + 4)(x - 4)

Explanation:

Step1: Use FOIL method

$(x + 4)(x - 4)=x\times x+x\times(-4)+4\times x + 4\times(-4)$

Step2: Simplify each term

$x\times x=x^{2}$, $x\times(-4)=-4x$, $4\times x = 4x$, $4\times(-4)=-16$
So we have $x^{2}-4x + 4x-16$

Step3: Combine like - terms

$-4x+4x = 0$, so the result is $x^{2}-16$

Answer:

$x^{2}-16$