# How do you foil (4x+y)(3x-4y)?

Jul 19, 2018

Using the foil, this expression simplifies to $12 {x}^{2} - 13 x y - 4 {y}^{2}$

#### Explanation:

Foil stands for first, outside, inside, and last and is associated with multiplication.

To foil this equation start by multiplying the first values of both sets of parentheses, 4x and 3x:

$4 x \cdot 3 x = 12 {x}^{2}$

Then multiply the outside values, 4x and -4y:

$4 x \cdot - 4 y = - 16 x y$

Nexxt, multiply the inside values, y and 3x:

$y \cdot 3 x = 3 x y$

Next, multiply the last values of both sets, y and -4y:

$y \cdot - 4 y = - 4 {y}^{2}$

Now combine the terms to form the expression:

$12 {x}^{2} - 16 x y + 3 x y - 4 {y}^{2}$

Combine like terms, giving you the final expression after using foil:

$12 {x}^{2} - 13 x y - 4 {y}^{2}$