# I need help simplifying ...

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• Jan 15th 2008, 07:56 AM
XIII13Thirteen
I need help simplifying ...
Help me simplify ...

$\displaystyle sqrt{90(2x-3y)^6}$
• Jan 15th 2008, 08:22 AM
TKHunny
Use parentheses to clarify meaning.

Do you mean this: $\displaystyle \sqrt{90*(2x-3y)^6}$?

Hints:

90 = 9*10

$\displaystyle (2x-3y)^{6}\;=\;[(2x-3y)^{3}]^{2}$

Let's see what you get.
• Jan 15th 2008, 09:12 AM
XIII13Thirteen
Quote:

Originally Posted by TKHunny
Use parentheses to clarify meaning.

Do you mean this: $\displaystyle \sqrt{90*(2x-3y)^6}$?

Hints:

90 = 9*10

$\displaystyle (2x-3y)^{6}\;=\;[(2x-3y)^{3}]^{2}$

Let's see what you get.

Thank you. I only just joined the forums today. I've tried to get the math text functions down as best I could. The function I was trying to write appears as you have typed it. I'll take your hints and see what I can do with them.
• Jan 15th 2008, 09:17 AM
XIII13Thirteen
I'm getting $\displaystyle (3x-4y)^3$

Is that correct? I multiplied the 90 into the equations making 180x-240y to 3x-4y
• Jan 15th 2008, 09:31 AM
topsquark
Quote:

Originally Posted by XIII13Thirteen
I'm getting $\displaystyle (3x-4y)^3$

Is that correct? I multiplied the 90 into the equations making 180x-240y to 3x-4y

Not quite. Think of it this way:
$\displaystyle \sqrt{90(3x - 4y)^6} = \sqrt{90} \cdot \sqrt{(3x - 4y)^6}$

What does $\displaystyle \sqrt{90}$ simplify to?

-Dan
• Jan 15th 2008, 02:19 PM
XIII13Thirteen
Quote:

Originally Posted by topsquark
Not quite. Think of it this way:
$\displaystyle \sqrt{90(3x - 4y)^6} = \sqrt{90} \cdot \sqrt{(3x - 4y)^6}$

What does $\displaystyle \sqrt{90}$ simplify to?

-Dan

$\displaystyle 3\sqrt{10}$
• Jan 15th 2008, 05:58 PM
XIII13Thirteen
So is it

$\displaystyle 3\sqrt{10} * [(2x-3y)^{3}]^{2}$ ?
• Jan 15th 2008, 08:37 PM
topsquark
Quote:

Originally Posted by XIII13Thirteen
So is it

$\displaystyle 3\sqrt{10} * [(2x-3y)^{3}]^{2}$ ?

Well, you forgot about your other square root.
$\displaystyle 3\sqrt{10} \cdot (2x - 3y)^3$

-Dan
• Jan 16th 2008, 05:37 AM
XIII13Thirteen
$\displaystyle 3\sqrt{10} \cdot \sqrt{[(2x - 3y)^3]^2}$

OK :). Thank you. I've been away from pre-cal for some time and I'm a bit rusty on factorization. I appreciate all of your help