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Mathematics 14 Online
OpenStudy (decarr432):

Please help URGENT!!!!

OpenStudy (decarr432):

OpenStudy (decarr432):

@zepdrix @mathmale

zepdrix (zepdrix):

\[\large\rm \frac{\color{orangered}{(a^{-1}b^3)^{3/4}}}{(ab)^{-3/4}}\]Deal with the numerator first. You'll need to apply this 3/4 exponent to BOTH the a and b separately.

zepdrix (zepdrix):

\[\large\rm (a^{-1})^{3/4}=a^?\]

OpenStudy (decarr432):

I don't understand how this works can you help me through it

zepdrix (zepdrix):

When you have an exponent being applied to multiple things, you have to give the exponent to each of them. Example: \(\large\rm (xy)^3=(x)^3(y)^3\) I had to give the 3 to both the x and the y. So here is what we're dealing with: \(\large\rm (a^{-1}b^3)^{3/4}=(a^{-1})^{3/4}(b^3)^{3/4}\) I gave the 3/4 exponent to each thing in the brackets.

OpenStudy (decarr432):

Okay so would it be A^-3/4?

zepdrix (zepdrix):

Yes, good. Your exponent rule tells you to `multiply` when you have a power and a power like that.

zepdrix (zepdrix):

How bout the b? What is 3 * 3/4?

OpenStudy (decarr432):

Wouldnt that give me a decimal?

zepdrix (zepdrix):

Well, we'd like to leave it in fraction form :\ Forgot how to multiply a whole number and fraction? Recall that a whole quantity can be written over 1. So 3 is 3/1. That will make it easier to multiply them together.

OpenStudy (decarr432):

A^6/4? or A^4/6?

zepdrix (zepdrix):

\[\large\rm 3\cdot\frac{3}{4}\quad=\frac{3}{1}\cdot\frac{3}{4}\quad=\frac{3\cdot3}{1\cdot4}\]

zepdrix (zepdrix):

No 6 :)

OpenStudy (decarr432):

my bad it would be nine lol XD

OpenStudy (decarr432):

Brain fart haha

zepdrix (zepdrix):

\[\large\rm \frac{\color{orangered}{(a^{-1}b^3)^{3/4}}}{(ab)^{-3/4}}\quad=\frac{\color{orangered}{a^{-3/4}b^{9/4}}}{(ab)^{-3/4}}\]Ok good, that takes care of the numerator.

OpenStudy (decarr432):

then it would be (A^-3/4 B^-3/4) right?

zepdrix (zepdrix):

Mmm k good.

OpenStudy (decarr432):

Anything else I should do?

zepdrix (zepdrix):

\[\large\rm \frac{a^{-3/4}b^{9/4}}{a^{-3/4}b^{-3/4}}\]

OpenStudy (decarr432):

It tells me to write it without negatives so just take them out?

zepdrix (zepdrix):

Nah, let's not do anything about the negatives just yet. Let's try to divide first, if we're able to.

zepdrix (zepdrix):

Notice the a's have the `exact same exponent`. What does that tell you? Anything? :)

OpenStudy (decarr432):

they divide evenly?

zepdrix (zepdrix):

Good good good, they divide evenly, or sometimes we call that "cancelling out"

zepdrix (zepdrix):

So we can just get rid of the a's.

zepdrix (zepdrix):

\[\large\rm \frac{b^{9/4}}{b^{-3/4}}\]

zepdrix (zepdrix):

Now apply your exponent division rule: \(\large\rm \dfrac{x^c}{x^d}=x^{c-d}\)

OpenStudy (decarr432):

okay so b^12?

zepdrix (zepdrix):

So your exponent is going to be 9/4 - (-3/4) right? Hmm I don't think that turns into a 12 0_o

OpenStudy (decarr432):

So a^12/8?

OpenStudy (decarr432):

or b i mean

zepdrix (zepdrix):

Ahh you gotta brush up on some of those basic math skills bruh :) When we add/subtract fractions, we only change the numerator If you have 9 of these things called "fourths" and you add 3 more of these "fourths" you get 12 of these "fourths", ya? They don't magically become some other type of thing.

OpenStudy (decarr432):

Okay

OpenStudy (decarr432):

Im bad at math lol sorry

zepdrix (zepdrix):

b^{12/4} Ok I think we can simplify this a tiny bit further :)

OpenStudy (decarr432):

b^3/1?

zepdrix (zepdrix):

Good good good. And a 1 is pretty insignificant, so we'll write it like this: b^3

zepdrix (zepdrix):

yay team \c:/ we did it!

OpenStudy (decarr432):

Okay

OpenStudy (decarr432):

I don't know how to put it all together now

OpenStudy (decarr432):

how would I write

zepdrix (zepdrix):

How would you write your final answer? Or you mean you have to explain the steps?

OpenStudy (decarr432):

Write the final answer

zepdrix (zepdrix):

The final answer simplified aaaaall the way down to b^3.

OpenStudy (decarr432):

really well darn lol

zepdrix (zepdrix):

The a's divided evenly, so poof, they vanished. And we applied exponent rule to turn the multiple b's into a single b

OpenStudy (decarr432):

Thanks your the best, I wish I learned this all when i was being taught it ;-; but I didn't thought I was coollol

zepdrix (zepdrix):

XD

OpenStudy (decarr432):

Time to rationalize the denominator

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