Question:
Tick (✓) the correct answer:
(x + 4)(x + 4) = ?
(a) (x2 + 16)
(b) (x2 + 4x + 16)
(c) (x2 + 8x + 16)
(d) (x2 + 16x)
Solution:
(c) $\left(x^{2}+8 x+16\right)$
$(x+4)(x+4)$
$\Rightarrow(x+4)^{2}$ (according to the formula $\left.(a+b)^{2}=a^{2}+2 a b+b^{2}\right)$
$\Rightarrow\left(x^{2}\right)+2(x)(4)+(4)^{2}$
$\Rightarrow x^{2}+8 x+16$