Mathematics
23 Online
OpenStudy (iwanttogotostanford):
HELP PLZ: Simplify 2 times square root 12 minus 2 square root 9 plus square root of 112.
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (iwanttogotostanford):
I got the last one btw
OpenStudy (studygurl14):
\(\Large 4\sqrt{24}-4\sqrt{8}+\sqrt{98}\)
OpenStudy (iwanttogotostanford):
yes @StudyGurl14
OpenStudy (studygurl14):
okay, so do you know how to simplify radicals?
OpenStudy (iwanttogotostanford):
kind of but for this one i forgot.
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
okay, let's start with 8. Try seperating it into its factors
OpenStudy (iwanttogotostanford):
4 and 2?
OpenStudy (studygurl14):
yep. keep going further. break down the 4
OpenStudy (iwanttogotostanford):
so break the 4 to 2 and 2
OpenStudy (studygurl14):
yep, so 8 = 2*2*2
Now, watch the magic:
\(\Large\sqrt{8}=\sqrt{2\times2\times2}=\sqrt{2^2\times2}=2\sqrt{2}\)
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
do you see how that worked?
OpenStudy (iwanttogotostanford):
yeah !
OpenStudy (iwanttogotostanford):
that actually did help a lot thanks!
OpenStudy (studygurl14):
actually, I just realized when didn't even have to break down the 4, because I'm sure you already know \(\sqrt{4}=2\)
OpenStudy (iwanttogotostanford):
yes
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
Yep, and since we had \(\Large-4\sqrt{8}\)...\(\Large-4(2\sqrt{2}=-8\sqrt{2}\)
Now, do you think you could do the same with \(\Large 4\sqrt{24}\)?
OpenStudy (iwanttogotostanford):
yes, so do I simplify inside the radical first? or the 4.
OpenStudy (iwanttogotostanford):
@StudyGurl14
OpenStudy (studygurl14):
inside the radical
OpenStudy (iwanttogotostanford):
@StudyGurl14 so i would get 6 and 4
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (iwanttogotostanford):
@StudyGurl14
OpenStudy (studygurl14):
yep, so you'd get \(\Large 4\sqrt{24}=4\sqrt{6\times4}=?\)
OpenStudy (iwanttogotostanford):
would I factor out the 6 or the 4
OpenStudy (studygurl14):
the 4, because it can easily be turned into 2
OpenStudy (iwanttogotostanford):
oh ok! so I would now have 8 on the outside of the radical correct?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
yep! So, so far we have:\(\Large 8\sqrt{6}-8sqrt{2}+\sqrt{98}\)
Can you do the last one now?
OpenStudy (iwanttogotostanford):
how did u get the 98
OpenStudy (studygurl14):
that's part of the original equation, remember? We haven't simplified that one yet
OpenStudy (iwanttogotostanford):
oh yea
OpenStudy (iwanttogotostanford):
i can't think off the top of my head what goes into 98....
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
well...it's an even number right? so try dividing it by 2
OpenStudy (studygurl14):
tell me what you get
OpenStudy (iwanttogotostanford):
49!
OpenStudy (studygurl14):
right! and what's \(\sqrt{49}\)?
OpenStudy (iwanttogotostanford):
8 would be the factor!
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (iwanttogotostanford):
wait no, 7 sorry
OpenStudy (studygurl14):
:) right. so can you finish simplifying that one?
OpenStudy (iwanttogotostanford):
well, i would have 7 on the outside of the radical and then 7 on the inside right? but then what?
OpenStudy (studygurl14):
no, almost \(\Large\sqrt{98}=\sqrt{49\times 2}=7\sqrt{2}\)
OpenStudy (iwanttogotostanford):
im a little confused on this last step, i really want to learn but just still a lil confused
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
What exactly are you confused about?
OpenStudy (iwanttogotostanford):
well, what to do exactly next or how to know what to do next
OpenStudy (studygurl14):
Oh, okay. So now we have \(\Large 8\sqrt{6}-8\sqrt{2}+7\sqrt{2}\) right?
OpenStudy (iwanttogotostanford):
yes
OpenStudy (studygurl14):
Okay, so notice how both the -8 and 7 have a sqrt 2?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (iwanttogotostanford):
yep!
OpenStudy (studygurl14):
You can combine them like normal numbers. What is -8 + 7?
OpenStudy (iwanttogotostanford):
-1!
OpenStudy (studygurl14):
yep, so you get \(\Large 8\sqrt{6}-\sqrt{2}\)
You're done
OpenStudy (iwanttogotostanford):
oh wow, ok so what happened to the 98 again?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (studygurl14):
Remember, 98 = 49 times 2, so...\(\Large\sqrt{98}=\sqrt{49\times 2}=\sqrt{49}\times\sqrt{2}=7\sqrt{2}\)
OpenStudy (iwanttogotostanford):
and could i please have your help on one more?? you were super helpful and i actually learned
OpenStudy (studygurl14):
Make sense?
OpenStudy (iwanttogotostanford):
yes, completely!
OpenStudy (studygurl14):
Great. :) and yes, I'll help you with another, but in a new thread, since this one is awfully long now
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (iwanttogotostanford):
ok, thank you!