# Thread: Simplifying Expressions... Not sure which kinds

1. ## Simplifying Expressions... Not sure which kinds

Ok, I'm going to post 3 so I can be sure of how to do each kind.
$\displaystyle \frac {6}{x^2-9x+20} * (5x-25)$

$\displaystyle \frac {2x-6}{x^2+5x-24} * \frac {x^2+6x-16}{3x}$

$\displaystyle \frac {(\frac {3x^2}{8x^5} * 2x^3)}{\frac {9x}{8x^2}}$

2. Originally Posted by jscalalamoboy
Ok, I'm going to post 3 so I can be sure of how to do each kind.
$\displaystyle \frac {6}{x^2-9x+20} * (5x-25)$
$\displaystyle \frac{6\cdot 5(x-5)}{(x-4)(x-5)}=\frac{30(x-5)}{(x-4)(x-5)}=\frac{30}{(x-4)}$

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$\displaystyle \frac{(3x^{2})(2x^{3})}{8x^{5}}\times \frac{8x^{2}}{9x}$

$\displaystyle \frac{3x(2x^{4})}{9x(8x^{3})}=\frac{2x^{4}}{3(8x^{ 3})}=\frac{2x^{4}}{24x^{3}}=\frac{x}{12}$

3. Originally Posted by jscalalamoboy
Ok, I'm going to post 3 so I can be sure of how to do each kind.

$\displaystyle \frac {2x-6}{x^2+5x-24} * \frac {x^2+6x-16}{3x}$
$\displaystyle \frac{2x-6}{x^2+5x-24} = \frac{2(x-3)}{(x+8)(x-3)} = \frac{2}{x+8}$

$\displaystyle \frac{x^2+6x-16}{3x} = \frac{(x+8)(x -2)}{3x}$

so the product is $\displaystyle \frac{2}{x+8}\cdot \frac{(x+8)(x-2)}{3x}$

$\displaystyle = \frac{2(x+8)(x-2)}{3x(x+8)} = \frac{2(x-2)}{3x}$