A community for students.
Here's the question you clicked on:
 0 viewing
cuppycake
 3 years ago
Choose the correct product of (5x + 4)2.
25x2 + 40x + 16
25x2 − 16
25x2 + 16
25x2 − 40x + 16
cuppycake
 3 years ago
Choose the correct product of (5x + 4)2. 25x2 + 40x + 16 25x2 − 16 25x2 + 16 25x2 − 40x + 16

This Question is Closed

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

brinethery
 3 years ago
Best ResponseYou've already chosen the best response.2First, 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

cuppycake
 3 years ago
Best ResponseYou've already chosen the best response.0ah wow thanks so much!

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

Law&Order
 11 months ago
Best ResponseYou've already chosen the best response.0@phi @CrazyMexican816

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

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

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

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

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

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

phi
 11 months ago
Best ResponseYou've already chosen the best response.1yes. 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

phi
 11 months ago
Best ResponseYou've already chosen the best response.1in 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)

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

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

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

phi
 11 months ago
Best ResponseYou've already chosen the best response.1let'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 ?

Law&Order
 11 months ago
Best ResponseYou've already chosen the best response.05x(5x+4)+4(5x+4) 25x^2•20x+20x+16 ohhhhhh thx @phi

phi
 11 months ago
Best ResponseYou've already chosen the best response.1the 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 \[ 25x^2 +40x +16\]
Ask your own question
Sign UpFind more explanations on OpenStudy
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.