Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
cuppycake
Group Title
Choose the correct product of (5x + 4)2.
25x2 + 40x + 16
25x2 − 16
25x2 + 16
25x2 − 40x + 16
 2 years ago
 2 years ago
cuppycake Group Title
Choose the correct product of (5x + 4)2. 25x2 + 40x + 16 25x2 − 16 25x2 + 16 25x2 − 40x + 16
 2 years ago
 2 years ago

This Question is Closed

brinethery Group TitleBest ResponseYou've already chosen the best response.2
(5x+4)(5x+4) Do you know how to use the FOIL method?
 2 years ago

brinethery Group TitleBest ResponseYou've already chosen the best response.2
First, Outer, Inner, Last. Your first terms that you need to multiply are 5x and 5x 5x*5x = 25x^2 Your outer terms that you need to multiply are 5x and 4. 5x*4 = 20x Your inner terms that you need to multiply are 5x and 4. 5x*4 = 20x You last terms that you need to multiply are 4 and 4. 4*4 = 16 So you have 25x^2, 20x, 20x, and 16 that you need to "combine." 25x^2 +20x +20x +16 = 25x^2 +40x +16
 2 years ago

cuppycake Group TitleBest ResponseYou've already chosen the best response.0
ah wow thanks so much!
 2 years ago

brinethery Group TitleBest ResponseYou've already chosen the best response.2
Watch this :) http://www.youtube.com/watch?v=Twtdsp0a1Iw
 2 years ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
@phi @CrazyMexican816
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
is this correct
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
i still dont nderstand @phi
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
i dont know anything?
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
see Khan's vide if you have time http://www.khanacademy.org/math/algebra/multiplyingfactoringexpression/multiplyingbinomials/v/multiplyingbinomials
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
i know that \(\color{lime}{\huge\ (5x+4)^2~}\) = 25x^2+16 but i dont understand if i add a 40x
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
in FOIL i use 5x^2+4^2 but dont get why did they add a 40x?
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
do you know what you get when you multiply a(x+y)
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
yes. now what if a was "complicated" in other words, if a was shorthand for (c+d) ? we would get (c+d)x + (c+d)y (I just replaced "a" with its equivalent (c+d) ) now we do the "distributive property" again: (c+d)x is the same as x(c+d), or, xc +xd and (c+d)y is cy + dy
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
in other words (c+d)(x+y) can be written as xc + xd +yc +yd we get FOUR terms (which would come from using FOIL, if you learn that)
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
foil is first out inner last
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
with (5x+4)(5x+4) we will get 4 terms, but we can combine two of the terms, and get 3 terms in the end
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
BTW i hope you dont ge confused cuz it looks like (5x + 4)•2 but it is (5x + 4)^2
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
let's use the distributive idea to do (5x+4)(5x+4) First, let a= (5x+4) so it's easier to see what we are doing: a(5x+4)= a*5x +a*4 now replace a with (5x+4) (5x+4)*5x + (5x+4)*4 now expand both terms: can you do that ?
 5 months ago

Law&Order Group TitleBest ResponseYou've already chosen the best response.0
5x(5x+4)+4(5x+4) 25x^2•20x+20x+16 ohhhhhh thx @phi
 5 months ago

phi Group TitleBest ResponseYou've already chosen the best response.1
the first part 5x(5x+4) is written as 25x^2 +20x so you get all together \[ 25x^2 +20x +20x +16\] the last step is notice we have 20 x's plus 20 more x's which is 40 x's. we write \[ 25x^2 +40x +16\]
 5 months ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.