Simplify (x+4) ^2 how is this simplified

Answer: x^2 + 8x + 16

Explanation:

each term in the second bracket must be multiplied by each term in the first bracket

⇒ (x + 4) ^2 = (x+4) (x+4) ⇒ (x+4 (x+4)

=x (x+4) + 4 (x+4)

= (x*x) + (x*4) + (4*x) + (4*4)

=x2+4x+4x+16

=x^2+8x+16

That's all

Is known that

(a + b) ² = a² + 2. a. b + b²

So:

(x + 4) ² = x² + 2. x. 4 + 4² = x² + 8x + 16