Find Square Root: Look at the first term, 16u2, and find its square root. The square root of 16u2 is 4u.
Check Last Term: Look at the last term, 25, and find its square root. The square root of 25 is 5.
Verify Middle Term: Check the middle term, −40u, to see if it equals 2 times the product of the square roots of the first and last terms. 2×4u×5=40u, but we need −40u, so it checks out.
Write Factored Form: Write the factored form using the square roots from steps 1 and 2. The expression (4u−5)2 equals 16u2−2×4u×5+25, which is our original expression.