How do you simplify #(x+9)(x+2)#?

3 Answers
Apr 5, 2018

#x^2+11x+18#

Explanation:

USE FOIL:

FIRST: Multiply #x# by #x# to get #x^2#
OUTSIDE: Multiply #x# by 2 to get #2x#
INSIDE: Multiply #x# by 9 to get #9x#
LAST: Multiply 9 by 2 to get 18

Then add each answer together to get #x^2+2x+9x+18#
Which simplifies to #x^2+11x+18#

#x^2 + 9x +2x + 18#
#x^2 +11x +18#

Explanation:

#x# times #x#, #x# times #2#, #9# times #x#, #9# times #2#

Apr 6, 2018

#x^2+11x+18# using FOIL

Explanation:

We can simplify thus using the highly useful mnemonic FOIL, standing for Firsts, Outsides, Insides, Lasts. You'll see we'll multiply the first terms, outside terms, inside terms and last terms. Here's a breakdown:

  • First terms: #x*x=color(blue)(x^2)#
  • Outside terms: #x*2=color(blue)(2x)#
  • Inside terms: #9*x=color(blue)(9x)#
  • Last terms: #9*2=color(blue)(18)#

Thus, we have:

#color(blue)(x^2+2x+9x+18)#

Which simplifies to

#color(blue)(x^2+11x+18)#

Hope this helps!