# possibly wrong answer in the book concerning exponent simplfying?

• May 18th 2011, 04:16 PM
math69
possibly wrong answer in the book concerning exponent simplfying?
$-2x^-3 * 5x^4 / 20x^-6$

in the book the answer is $-1/2x^5$

but i got $-1/2x^7$ and so did my algebra program, the confusion is when your bring the -6 up, in the book it subtracts, can anyone shed some light?
thx

btw the -3 and -6 are neg. exponents, the program didnt bring em up for some reason sorry iam new
• May 18th 2011, 04:57 PM
Quacky
Quote:

Originally Posted by math69
$-2x^-3 * 5x^4 / 20x^-6$

in the book the answer is $-1/2x^5$

but i got $-1/2x^7$ and so did my algebra program, the confusion is when your bring the -6 up, in the book it subtracts, can anyone shed some light?
thx

btw the -3 and -6 are neg. exponents, the program didnt bring em up for some reason sorry iam new

I agree with your answer. It seems to be a straightforward application of $(x^a)(x^b)=x^{a+b}$
• May 18th 2011, 07:17 PM
math69
yea and its an example problem too, confusing