# How do you multiply (a + b)(c + d)?

Oct 10, 2016

$\left(a + b\right) \left(c + d\right) = a c + b c + a d + b d$

#### Explanation:

To multiply $\left(a + b\right) \left(c + d\right)$,

let us first consider $\left(a + b\right)$ as single number

and applying distributive property.

$\left(a + b\right) \left(c + d\right)$

= $\left(a + b\right) \times c + \left(a + b\right) \times d$

Now on each of the two i.e. $\left(a + b\right) \times c$ and $\left(a + b\right) \times d$

can again be simplified using distributive property, as follows

$a \times c + b \times c + a \times d + b \times d$

= $a c + b c + a d + b d$