Factor 4w^2-36w+81

$4 w^{2} - 36 w + 81$

Step 1

Rewrite $4 w^{2}$ as ${(2 w)}^{2}$ .

${(2 w)}^{2} - 36 w + 81$

Step 2

Rewrite $81$ as $9^{2}$ .

${(2 w)}^{2} - 36 w + 9^{2}$

Step 3

Check that the middle term is two times the product of the numbers being squared in the first term and third term.

$36 w = 2 \cdot (2 w) \cdot 9$

Step 4

Rewrite the polynomial.

${(2 w)}^{2} - 2 \cdot (2 w) \cdot 9 + 9^{2}$

Step 5

Factor using the perfect square trinomial rule $a^{2} - 2 a b + b^{2} = {(a - b)}^{2}$ , where $a = 2 w$ and $b = 9$ .

${(2 w - 9)}^{2}$