# Simplifying rational expressions

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• January 14th 2010, 09:36 PM
iDrum
Simplifying rational expressions
Any help with these would be greatly appreciated thank you!

6.) (x^2 - 36) * [(3x + 1) / (x + 6)]

(y^2 - 9) / [(y + 3) / (y - 3)]
• January 14th 2010, 09:50 PM
pickslides
Quote:

Originally Posted by iDrum
Any help with these would be greatly appreciated thank you!

6.) (x^2 - 36) * [(3x + 1) / (x + 6)]

(y^2 - 9) / [(y + 3) / (y - 3)]

You need to use the difference of 2 squares rule on both problems.

It is $a^2-b^2= (a-b)(a+b)$

Here's a kick start

$
x^2 - 36 = x^2 - 6^2 = (x-6)(x+6)
$
• January 14th 2010, 10:01 PM
bigwave
Quote:

Originally Posted by iDrum
Any help with these would be greatly appreciated thank you!

6.) (x^2 - 36) * [(3x + 1) / (x + 6)]

(y^2 - 9) / [(y + 3) / (y - 3)]

rewrite
$\frac {y^2-9}{1}\ \frac{y-3}{y+3}$

then
$\frac {(y+3)(y-3)}{1}\ \frac{y-3}{y+3}$

see the rest?