# How do you foil (–x – 3)(3x + 20)?

Aug 28, 2015

(–x – 3)(3x + 20)=color(blue)(-(3x^2+29x+60)

#### Explanation:

The expression is : (-x−3)(3x +20)

F O I L involves carrying out the below operations in the following order:

1) product of First terms :$\left(\textcolor{b l u e}{- x \mathmr{and} 3 x}\right)$+

2)product of Outside terms:$\left(\textcolor{b l u e}{- x \mathmr{and} 20}\right)$+

3)product of Inside terms:$\left(\textcolor{b l u e}{- 3 \mathmr{and} 3 x}\right)$+

4)product of Last terms:$\left(\textcolor{b l u e}{- 3 \mathmr{and} 20}\right)$

1) $- x \cdot 3 x = \textcolor{b l u e}{- 3 {x}^{2}} +$

2) $- x \cdot 20 = \textcolor{b l u e}{- 20 x} +$

3) $- 3 \cdot 3 x = \textcolor{b l u e}{- 9 x} +$

4) -3 *20 = color(blue)(-60

=color(blue)(-3x^2-20x-9x-60
=color(blue)(-3x^2-29x-60
=color(blue)(-(3x^2+29x+60)