Factor x^2-1.8x+0.81

$x^{2} - 1.8 x + 0.81$

Step 1

Rewrite $0.81$ as ${0.9}^{2}$ .

$x^{2} - 1.8 x + {0.9}^{2}$

Step 2

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

$1.8 x = 2 \cdot x \cdot 0.9$

Step 3

Rewrite the polynomial.

$x^{2} - 2 \cdot x \cdot 0.9 + {0.9}^{2}$

Step 4

Factor using the perfect square trinomial rule $a^{2} - 2 a b + b^{2} = {(a - b)}^{2}$ , where $a = x$ and $b = 0.9$ .

${(x - 0.9)}^{2}$