# How do you factor the expression d^2-14d+49?

Jun 19, 2018

${\left(d - 7\right)}^{2}$

#### Explanation:

$\text{this is a "color(blue)"perfect square}$

•color(white)(x)(a+-b)^2=a^2+-2ab+b^2

$\text{here "a=d" and } b = - 7$

$2 a b = 2 \times d \times - 7 = - 14 d$

${d}^{2} - 14 d + 49 = {\left(d - 7\right)}^{2}$