# How do you factor xy-7x+7y-49?

Jun 1, 2017

$\left(x + 7\right) \left(y - 7\right)$

#### Explanation:

Given: $x y - 7 x + 7 y - 49$

Use group factoring. Group the first and third terms and the second and fourth terms:

$\left(x y + 7 y\right) + \left(- 7 x - 49\right)$

Factor the greatest common factor (GCF) of each group:

$y \left(x + 7\right) - 7 \left(x + 7\right)$

Notice that both contain the factor $x + 7$. This is the GCF of both groups:

$\left(x + 7\right) \left(y - 7\right)$