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Algebra help! Simplify completely?
Simplify completely: [cube root (x^6y^4 / 3z^3) ] * [cube root (81x^9y^-10z^6) ]
Y is raised to the power of -10...you just read the problem differently
2 Answers
- RaymondLv 79 years agoFavourite answer
CubeRoots (like square roots or any other level of roots) can be "distributed" over products.
CubeRoot(a) * CubeRoot(b) =
CubeRoot(ab)
Multiply (x^6y^4 / 3z^3)
by (81x^9y^2-10z^6)
*** you are missing the exponent for y in the second cubeRoot **
I am using 2 for now, but you have to do the problem with the real one in your problem
and you get [(27x^15 y^6 / z^3) - (10/3)x^6 y^4 z^3]
From here, it gets tricky, as a root can NOT be distributed over sums and differences
cubeRoot(a-b) is NOT the same as cubeRoot(a) - cubeRoot(b)
try to factor out common stuff.
[(27x^15 y^6 / z^3) - (10/3)x^6 y^4 z^3]
I would factor out 27 (yes), x^6, y^6 and z^3
to get:
(27x^6 y^6 z^3) [(x^9 / z^6) - (10/81)/y^2 ]
What do we have, so far?
cubeRoot(x^6y^4/3z^3) * cubeRoot(81x^9y^2 - 10z^6)
becomes
cubeRoot [(27x^15 y^6 / z^3) - (10/3)x^6 y^4 z^3]
becomes
cubeRoot {(27x^6 y^6 z^3) [(x^9 / z^6) - (10/81)/y^2 ]}
becomes
cubeRoot(27x^6 y^6 z^3) * cubeRoot[(x^9 / z^6) - (10/81)/y^2 ]
solve the first root:
3x^2y^2z * cubeRoot[(x^9 / z^6) - (10/81)/y^2 ]
The next step is to factor the remaining part of the root. In such problems, you normally get a "difference of powers" where there are tricks to factor. But because I do not know the original power of y, I would only be guessing.
- MoonLv 79 years ago
The question has not been written properly, and apparently carries some mistakes.
First ensure the accuracy!