# What happens when you square a binomial?

##### 1 Answer
Aug 16, 2015

I am not sure about what you need, but have a look:

#### Explanation:

If you have a binomial such as $\left(a + b\right)$ and you square it you get:
${\left(a + b\right)}^{2}$
but this is the same as:
$\left(a + b\right) \left(a + b\right)$

exactly as ${4}^{2} = 4 \times 4$.

The result of $\left(a + b\right) \left(a + b\right)$ is interesting because you need to multiply each term of the first bracket by each term of the second and add the results!
$\left(a + b\right) \left(a + b\right) = a \cdot a + a \cdot b + b \cdot a + b \cdot b = {a}^{2} + 2 a b + {b}^{2}$

Try by yourself with a difficult one: ${\left(a - b\right)}^{2}$ remembering to consider the signs of each term!