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Simplifying exponential expressions

arl2267

New member
Nov 6, 2012
15
Simplify 8p-3 x (4p2)-2/p-5.

This is what I got:

First thing I did was flip everything to get rid of the negative exponents:

p5/8p3x(4p2)2

next thing I did was multiply the 4p2 by 2

p5/ 8p3x16p4


Then I subtracted thep5 from the 8p3

p2/8x16p4

and ended up with

1/128p2 I know that the answer is 1/2p2​ so where did I go wrong?
 
Last edited by a moderator:

pickslides

Member
Feb 1, 2012
57
After expanding the brackets

$\displaystyle \frac{8p^{-3}\times 4^{-2}\times p^{-4}}{p^{-5}}$

$\displaystyle \frac{8p^{-3}\times p^{-4}}{4^{2}\times p^{-5}}$

You can now see the numerical part is $\displaystyle\frac{8}{16}= \frac{1}{2}$
 

MarkFL

Administrator
Staff member
Feb 24, 2012
13,775
In your first step where you "flip" everything, you cannot do this with the 8 since it does not have a negative exponent. If you had left the 8 in the numerator, then you would have gotten the desired result.

edit: Welcome to the forum, and I certainly appreciate the fact that you show your work...this makes it much easier to address where your error(s) may be.:cool: