How do you foil #(–x – 3)(3x + 20)#?

1 Answer
Aug 28, 2015

Answer:

#(–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 :#(color(blue)(-x and 3x))#+

2)product of Outside terms:#(color(blue)(-x and 20))#+

3)product of Inside terms:#(color(blue)(-3 and 3x))#+

4)product of Last terms:#(color(blue)(-3 and 20))#

1) #-x *3x=color(blue)(-3x^2) +#

2) #-x* 20=color(blue)(-20x)+#

3) #-3 * 3x = color(blue)(-9x)+#

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

adding all the terms

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