$\displaystyle -2x^-3 * 5x^4 / 20x^-6$

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

but i got $\displaystyle -1/2x^7$ 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