# What is the standard form of y= (x+3) (4x+1) ?

Dec 27, 2015

$y = 4 {x}^{2} + 13 x + 3$

#### Explanation:

Use FOIL to multiply out...

$\left(x + 3\right) \left(4 x + 1\right) = \stackrel{\text{First" overbrace(x*4x) + stackrel "Outside"overbrace(x*1) + stackrel "Inside" overbrace(3*4x) + stackrel "Last}}{\overbrace{3 \cdot 1}}$

$= 4 {x}^{2} + x + 12 x + 3 = 4 {x}^{2} + 13 x + 3$

Standard form has individual terms in descending order of degree of $x$. If the binomial factors are expressed in the form $\left(a x + b\right)$ then the result of FOIL will be in the right order, just requiring the combination of the middle terms.