Ask your own question, for FREE!
Mathematics 15 Online
OpenStudy (anonymous):

Algebra 2 help (attachment)

OpenStudy (anonymous):

OpenStudy (anonymous):

Can someone walk me through one or 2 problems?

OpenStudy (anonymous):

Hmm, it's basically rewriting the equations in a different way.

OpenStudy (anonymous):

For example the 3rd equation

OpenStudy (anonymous):

okay

OpenStudy (anonymous):

for some reason i can't use the equation button anymore, it worked before

OpenStudy (anonymous):

okay just tell me in words maybe?

OpenStudy (anonymous):

ok

OpenStudy (anonymous):

can you break the number 27 down to it's prime factors?

OpenStudy (anonymous):

27 /\ 3 x 9 /\ 3 x 3

OpenStudy (anonymous):

indeed

OpenStudy (anonymous):

so you agree with me that the cube root of 27 can also be written as (3^3)^(1/3) (sorry for the format, i hope you understand

OpenStudy (anonymous):

basically the cube root of 3 to the power of three (or in other words, just 3)

OpenStudy (anonymous):

is the 1/3 the exponent?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

okay

OpenStudy (anonymous):

1/3 in the exponent is the same as the cube root (it's a different way of writing a root)

OpenStudy (anonymous):

so can i just write 3 as cubed not 1/3 ?

OpenStudy (anonymous):

hmm, i guess yes if i understand the question correctly

OpenStudy (anonymous):

(3^3)^3

OpenStudy (anonymous):

for example, square root of 4 is the same as 4^1/2 and the cube root of 4 is 4^1/3... etc.

OpenStudy (anonymous):

so can i just say (3^3)^3 ?

OpenStudy (anonymous):

no, that's a much bigger number.

OpenStudy (anonymous):

oh ok

OpenStudy (anonymous):

so how did u get 1/3 from the problem

OpenStudy (anonymous):

it's the cube root of (3^3)

OpenStudy (anonymous):

I know how you got 3^3, but idk how you got 1/3

OpenStudy (anonymous):

how did you know that..

OpenStudy (anonymous):

OpenStudy (anonymous):

you see that image?

OpenStudy (anonymous):

yes okay I see it

OpenStudy (anonymous):

so what do I do next

OpenStudy (anonymous):

OpenStudy (anonymous):

I made a second picture, hope that clears things up

OpenStudy (anonymous):

Okay thank you!

OpenStudy (anonymous):

The steps are clear then?

OpenStudy (anonymous):

Shall i do the 4th as well or do you think you can solve the others on your own?

OpenStudy (anonymous):

wait so what would be the answer to the 3rd one?

OpenStudy (anonymous):

the square root of 3 can't be simplyfied, so it's smply 3 times the square root of 3 (the 3 comes from the cube root of 27)

OpenStudy (anonymous):

so it's (3^3)^1/3

OpenStudy (anonymous):

that's the cube root of 27

OpenStudy (anonymous):

which results in 3. but you also have the square root of 3.

OpenStudy (anonymous):

Which means, the end result is SQRT(3) * 3

OpenStudy (anonymous):

Roots of prime numbers can't be simplyfied

OpenStudy (anonymous):

okay let's do 4

OpenStudy (anonymous):

So you always break the numbers under the root down to their prime factors, then simplify, it's usually the easiest method

OpenStudy (anonymous):

Okay hold on then

OpenStudy (anonymous):

Right, so in equation 4, you have two cube roots. The cube root of 45 and the cube root of 75. It would be easier to just multiply 45 and 75 and take the cube root of the result. (it'll give the same answer)

OpenStudy (anonymous):

that way you'll only need to do it once.

OpenStudy (anonymous):

45 / \ 5 9 / / \ 5 3 3

OpenStudy (anonymous):

i got 15

OpenStudy (anonymous):

Correct, you figured that out quite fast

OpenStudy (anonymous):

okay, what do I do next

OpenStudy (anonymous):

What did you do to arrive at 15?

OpenStudy (anonymous):

45 x 75 and cube root

OpenStudy (anonymous):

You did the cube root of 45*75 from the top of your head or did you use a calculator for it?

OpenStudy (anonymous):

calculator lol i wouldnt be able to do that in my head

OpenStudy (anonymous):

alright, i wouldn't either, but i still can with some simple steps and i'm sure you can too. let me show you.

OpenStudy (anonymous):

no that's okay! but thanks

OpenStudy (anonymous):

so is that the answer?

OpenStudy (anonymous):

15?

OpenStudy (anonymous):

Yes 15 is the end result.

OpenStudy (anonymous):

If you take 45 and 75 and break them both up in their prime factorials

OpenStudy (anonymous):

can we also do numbers 7 and 8?

OpenStudy (anonymous):

you'll get 5*3*3*5*5*3

OpenStudy (anonymous):

sure

OpenStudy (anonymous):

but do you see now why it's 15?

OpenStudy (anonymous):

yes!

OpenStudy (anonymous):

Alight, let's see if you can do the same in the next question then

OpenStudy (anonymous):

oh 7 is a different type let me see

OpenStudy (anonymous):

you can't really do anything with the x, so that will just stay as it is, so the only thing you'd have to do is simplify the square root of 36 and multiply the outcome of that with the square root of x^3

OpenStudy (anonymous):

6x3

OpenStudy (anonymous):

where did you get the 3 from?

OpenStudy (anonymous):

6x^3 *

OpenStudy (anonymous):

oh right, yes.

OpenStudy (anonymous):

except

OpenStudy (anonymous):

the x is still under the root

OpenStudy (anonymous):

the 6 isn't, of course.

OpenStudy (anonymous):

so to be clear 6*SQRT(x^3)

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

what about 8?

OpenStudy (anonymous):

Same story, x and y can't be simplified, so only the cube root of 125 can be simplyfied, the x and y stay exactly as they are (including the root)

OpenStudy (anonymous):

cube root of 125 can easily be done from your head as well, if you use prime factors like i explained before.

OpenStudy (anonymous):

5

OpenStudy (anonymous):

Yes

OpenStudy (anonymous):

5y^2z^4

OpenStudy (anonymous):

ye except you forgot the root once again ;)

OpenStudy (anonymous):

square root over the whole asnwer?

OpenStudy (anonymous):

answer*

OpenStudy (anonymous):

no, cube root over y and z, but not the 5.

OpenStudy (anonymous):

the 5 is the result of 'freeing' the 125 from the cube root. But since it's unknown what y and z are exactly, they are stuck under the root, they can't be 'freed' so they stay in root prison so to speak.

OpenStudy (anonymous):

oh okk! what about 9? last one if u have time

OpenStudy (anonymous):

Sure. that one is important to understand as well

OpenStudy (anonymous):

Obviously, you don't know what k is, so you can't simplify k itself, but you can still write it in another way because

OpenStudy (anonymous):

remember how i said a square root can be written as "to the power of one half" ?

OpenStudy (anonymous):

so basically you have the square root of 18, times k to the power of 6 halves.

OpenStudy (anonymous):

does that make sense or should i paint it?

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!