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Can someone PLEASE explain how to simplify square roots with variables and eexponents in them?? I'd also be thankful if you explained step-by-step how to

solve (16x^4)^3/2 and how to simplify 3y^4/3 times 3yx^1/2? I have to do a retake on my math test and I REALLY need help!

1 Answer

3 votes
x^a/b is
\sqrt[b]{x^a} . The way I memorise that is x^1/3 is the cubic root of x. Do you get it? In that case, x is raised to a power of 1 and the cubic root is practically has a power of 3.
In your example,


\sqrt[ (3)/(2) ]{16 x^4} is practically square rooting each term then cubing them individually. Remember when square-rooting any index you halve it. I'll elaborate:


√(x^4) =
x^(2)

√(16) = 4
Then cube each,

4^3 = 64
and
( x^(2) )^3 =
x^(6)

As for the 2nd part: you must use the rules of indices.

x^(a) * x^(b) = x^(a+b)
So breaking the question up:

3 * 3 = 9

x^{ (1)/(2) } stays as is since the 2nd term does not contain x
now:

y^{ (4)/(3) } * y^(1) = y^{ (4)/(3) + 1 } = y^{ (4)/(3) + (3)/(3) } = y^{ (7)/(3) }
This makes your final answer look like this:

9 x^{ (1)/(2) } y^{ (7)/(3) }

I hope that helped and good luck in your test!