# What is the standard form of y=(2x+4)(x-5) ?

Jul 24, 2018

$y = 2 {x}^{2} - 6 x - 20$

#### Explanation:

$y = \left(2 x + 4\right) \left(x - 5\right)$

Standard quadratic form is $y = a {x}^{2} + b x + c$.

Use FOIL to simplify:

Following this image, we can simplify/expand:
Firsts:
$2 x \cdot x = 2 {x}^{2}$

Outers:
$2 x \cdot - 5 = - 10 x$

Inners:
$4 \cdot x = 4 x$

Lasts:
$4 \cdot - 5 = - 20$

Combine them all together:
$y = 2 {x}^{2} - 10 x + 4 x - 20$

Combine the like terms $- 10 x$ and $4 x$:
$y = 2 {x}^{2} - 6 x - 20$

As you can see, this is in standard quadratic form $y = a {x}^{2} + b x + c$

Hope this helps!