simplify expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
ashley7357
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simplify expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)

Postby ashley7357 » Tue Jan 18, 2011 1:58 am

simplify the expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)

snowdrifter
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Re: simplify the expression

Postby snowdrifter » Tue Jan 18, 2011 3:19 am

ashley7357 wrote:simplify the expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)


I assume your question is: Simplify 4ab(sqrt(2b))-3a(sqrt(18b^3))=7ab(sqrt(6b))
In that case square both sides. The left side is of the equation is complicated but if you square it using
(x - y)^2 = x^2 -2xy + y^2 you will find that for this particular question you end up with a perfect square under the root in the 2xy term. Then it is a matter of gathering like terms.

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stapel_eliz
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Postby stapel_eliz » Tue Jan 18, 2011 1:19 pm

ashley7357 wrote:simplify the expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)

The instructions say to "simplify the expression", but the "equals" sign makes this an equation...?

aeb
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Re: simplify the expression

Postby aeb » Wed Jan 19, 2011 2:20 am

ashley7357 wrote:simplify the expression 4ab(sqrt2b)-3a(sqrt18b^3)=7ab(sqrt6b)

i do not unstand this please someone help ...[img] :confused :confused:

snowdrifter
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Re: simplify the expression

Postby snowdrifter » Wed Jan 19, 2011 4:20 am

To clarify, this was the question

Simplify:

And yes, we are simplifying an equation.

The first step is:

If you are careful with the algebra, you can eliminate all the radicals.

In fact, as long as b is not equal to zero you can solve this equation for a.



Which, I suppose, is as simple as it gets.


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