# What is the standard form of y= (x+3)(3x-4) ?

Apr 12, 2018

See a solution process below:

#### Explanation:

To put this equation in standard form we need to multiply the two terms on the right side of the equation. To multiply these two terms you multiply each individual term in the left parenthesis by each individual term in the right parenthesis.

$y = \left(\textcolor{red}{x} + \textcolor{red}{3}\right) \left(\textcolor{b l u e}{3 x} - \textcolor{b l u e}{4}\right)$ becomes:

$y = \left(\textcolor{red}{x} \times \textcolor{b l u e}{3 x}\right) - \left(\textcolor{red}{x} \times \textcolor{b l u e}{4}\right) + \left(\textcolor{red}{3} \times \textcolor{b l u e}{3 x}\right) - \left(\textcolor{red}{3} \times \textcolor{b l u e}{4}\right)$

$y = 3 {x}^{2} - 4 x + 9 x - 12$

We can now combine like terms:

$y = 3 {x}^{2} + \left(- 4 + 9\right) x - 12$

$y = 3 {x}^{2} + 5 x - 12$