A community for students.
Here's the question you clicked on:
 0 viewing
EmmaH
 2 years ago
Multiply: (3a + 11)(3a  11).
9a2  22
9a2  121
9a2 + 121
9a2  66a + 121
i know its either b or c but i donmt knwo which it is..
EmmaH
 2 years ago
Multiply: (3a + 11)(3a  11). 9a2  22 9a2  121 9a2 + 121 9a2  66a + 121 i know its either b or c but i donmt knwo which it is..

This Question is Closed

JayDS
 2 years ago
Best ResponseYou've already chosen the best response.0Do you know the crab claw/Foil method to expand out the brackets?

ZeHanz
 2 years ago
Best ResponseYou've already chosen the best response.2This is the form: (ab)(a+b) = a²b². It pays to learn this form by heart, so you can recognise them immediately when you see one!

precal
 2 years ago
Best ResponseYou've already chosen the best response.0this is a difference of squares as ZeHanz stated

JayDS
 2 years ago
Best ResponseYou've already chosen the best response.0yes it is indeed but she can easily get the answer if she expands the brackets and collect like terms as well.

EmmaH
 2 years ago
Best ResponseYou've already chosen the best response.0ii got the answer usinmg foil which is 9a^2+ (121)

ZeHanz
 2 years ago
Best ResponseYou've already chosen the best response.2FOILing is fine! It's just that in SOME cases, you don't need it, because you can see the answer right away. This is such a special case. Another one: (3p+4q)(3p4q). See: sum and difference of the same two numbers, so the answer is (3p)²(4q)²=9p²16q². You can save so much (spare) time with this...

EmmaH
 2 years ago
Best ResponseYou've already chosen the best response.0but my answermy answer possiblities are 9a2  22 9a2  121 9a2 + 121 9a2  66a + 121

JayDS
 2 years ago
Best ResponseYou've already chosen the best response.0The answer you got from FOILING is correct, 9a^2+ (121). but one thing, you forgot that +  becomes  9a^2 121

JayDS
 2 years ago
Best ResponseYou've already chosen the best response.0Also note for special cases as these u should learn them, so u are able to identify them straight away just as @ZeHanz shows it.

precal
 2 years ago
Best ResponseYou've already chosen the best response.0never use double signsdw:1359206802362:dw
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.