Hello.
No, (x+4)² doesn't equal x²+16.
Let's see why.
Remember that
x times x = x²
4 times 4 = 4²=16
So it seems like (x+4)² is equal to x²+16.
However,
(x+4)²≠x²+16.
Well, what IS that equal to?
Turns out that
(x+4)² is equal to x² + twice the product of x and 4 +16 (!)
(x+4)²=x²+2*4*x+4²
(x+4)²=x²+8x+16
Therefore, (x+4)²=x²+8x+16.
I hope it helps.
Have an outstanding day. :)
