I need help with this question:

2x^3 y^-28x^-2 y^-3

What its asking me to do is to simplify the question. Can anyone help me??

Printable View

- Jun 7th 2010, 12:54 PMGomaz23exponential functions
I need help with this question:

__2x^3 y^-2__8x^-2 y^-3

What its asking me to do is to simplify the question. Can anyone help me?? - Jun 7th 2010, 01:03 PMAmer
$\displaystyle \frac{2x^3y^{-2}}{8x^{-2}y^{-3}} $

$\displaystyle \left(\frac{2x^3}{8x^{-2}}\right)\left(\frac{y^{-2}}{y^{-3}}\right) $

you should know

$\displaystyle y^{-n} = \frac{1}{y^n} $

moving the number from the denominator to nominator change the exponent sign, so

$\displaystyle \left(\frac{2x^3}{8x^{-2}}\right) = \frac{2x^3 . x^2}{8}= \frac{2x^{3+2}}{8}= \frac{2x^5}{8} $

$\displaystyle \left(\frac{y^{-2}}{y^{-3}}\right) = y^{-2}. y^{3}= y^{-2+3} = y $

$\displaystyle \frac{2x^3y^{-2}}{8x^{-2}y^{-3}} = \frac{2x^5y}{8}=\frac{x^5y}{4}$