Answer
$$(a+4)(a+4)$$
Work Step by Step
$a^{2}+8a+16$
Step 1
Open 2 parenthesis; each starts with the square root of the first root. In this case $\sqrt a^{2}$$ = a$
Step 2
Find 2 numbers that:
- Multiplied by each other give you the last term: $16$
- Added (if the middle sign is positive) or subtracted (if the middle sign is negative) give you the middle term $8$.
In this case those numbers are 4 and 4.
Step 3
Write the solution.
The sign of the first parenthesis is the first sign in the original polynomial and the sign in the second parenthesis is the product of both signs in the polynomial.
$(a+4)(a+4)$