Divide (x^2+10x+21)/(x+3)

Consider the form ${\displaystyle x^2+bx+c}$. Find a pair of integers whose product is ${\displaystyle c}$ and whose sum is ${\displaystyle b}$. In this case, whose product is ${\displaystyle 21}$ and whose sum is ${\displaystyle 10}$.

Write the factored form using these integers.

Cancel the common factor.

Divide ${\displaystyle x+7}$ by ${\displaystyle 1}$.