someone please help me on simplifying expressions!
Do I need to make an example, or do you need help with a question?
it's questions, but I did some trying to use the methods you showed me but I get stuck :/
Okay
For your first one:
Be aware that the topic here is "exponentiation" and that you're being asked to simplify expressions with exponents.
yes, I'm sorry.
For Problem #59: Imagine you had (a/b)^(-1). How would you evaluate that?
In nicer format, that'd be \[(\frac{ a }{ b })^{-1}\]
do the reciprocal since it has a negative exponent? :/
Yes. Go ahead: try it.
1/ (a/b) ?
That's correct, but it'd be much easier simply to write b/a, don't you think?
\[(a/b)^{-1}=b/a\]
may I ask why b/a is easier than a/b because I'm kind of confused :/ ?
(2x^3 y^4)^5 2^5x^15 y^20 (32x^15 y^20) \[32x^15 y^20\]
thats question 68 and the last one is supposed to be 32^15 y^20
What I actually said was that your (correct)\[\frac{ 1 }{ a/b }\]is more simply expressed as b/a. I inverted (a/b) to obtain (b/a).
Simplify the following: \[x^2/(1/(x^3 y^2)) \]\[ x^2/(1/(x^3 y^2)) \]as a single fraction. Multiply the numerator of \[ \frac{x^2}{\frac{1}}{\frac{x^3 y^2}}\] by the reciprocal of the denominator. \[ \frac{x^2}{\frac{1}{x^3 y^2}} = x^2 x^3 y^2: \]\[x^2 x^3 y^2 \]Combine products of like terms. \[x^2 x^3 y^2 = x^{2+3} y^2:\]\[x^{2+3} y^2\]Evaluate 2+3. \[2+3 = 5: \]God, it's so hard to type fractions on fractions, sorry -.-
Oops that was a waste of time.
Too many helpers here, I'm afraid. Which one of us is going to bow out?
That'll be me, I helped her enough earlier :P
Sweet of you. Apparently you're not as dangerous as your name implies.
dominiquebee72 where's the 32 from..?
thank you all for helping, I appreciate it, if I haven't replied it's because i'm going over it :)
Here you see the danger in providing answers without explanations and without involving the person asking the question. Please, @dominiquebee72, help @heyitslizzy13 to find her own answers by providing her with guidance along the way.
thanks @mathmale I don't even know which problem to look at I'm so confused .-.
@heyitslizzy13 : Please look at Problem #59:\[(\frac{ x^2 }{ x ^{-3}y ^{-2} })^{-1}\]and then apply what I was demonstrating earlier. In other words, simply flip the quantity within the parentheses.
so x^3 y^2 / x^2 ?
@DangerousJesse thanks a lot for your help!! :)
If we invert the quantity inside parentheses, we'd get \[\frac{ x ^{-3}y ^{-2} }{ x^2 }\]... note that the exponent is now gone.
What's the last thing you'd do to simplify this? Remember, we don't want negative exponents.
wait what happened to the exponent on the outisde..? I thought the exponents would then be positive since we did the reciprocal ?
There was a negative 1 exponent. We got rid of that simply by inverting / flipping the quantity within the parentheses.
Or, as you say, we found the reciprocal of the original quantity within parentheses.
oh sorry, I thought you had to apply the -1 exponent to the numbers inside the parentheses
You certainly can do EITHER that OR flip the original quantity within parentheses. I chose to do the latter.
So, going back to \[\frac{ x ^{-3}y ^{-2} }{ x^2 }\]how are you going to eliminate those negative exponents?
reciprocal again?
That would work. What i'd suggest, however, is that you recognize that that \[x ^{-3}\]in the numerator becomes x^3 in the denominator. Can you agree with that? if so, what is (x^3)(x^2)?
x^5?
Yes. So your newest and last denominator is x^5. What happens to that \[y ^{-2}\]in the numerator?
Hint: re-write \[y ^{-2}\] with positive exponent.
y^2 / x^5 ?
i'm still not sure how I even got there .-.
that \[y ^{-2}\] becomes \[\frac{ 1 }{ y^2 }\]so,
\[\frac{ y ^{-2} }{ x^2 }\] becomes what?
sorry, I meant\[\frac{ y ^{-2} }{ x^5 }\]
x^5 / y^2 ?
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