Question

r^3r^-4/4^-2r^-5 i tried doing r^3/r^-2 x r-4/r-5 & got r^5,r^1 but the answer is r6, what am i doing wrong?

Answer 1

I will interpret your r^3r^-4/4^-2r^-5 as

r^3 r^-4/(4^-2 r^-5)
= r^-1/(...... wait, is that 4^-2 supposed to be r^-2 ???

anyway, if you got r^5 r^1, isn't that r^6 ???
(why is there a comma in r^5 r^1 ? )

Answer 2

the problem is r^3r^4/r^-2r^-5

Answer 3

then take a look at what you first typed.

ok then:
r^3r^4/r^-2r^-5
= r^(3+4-(-2)-5)
= r^4

if you meant:
r^3r^4/(r^-2r^-5)

= r^7 / r^-7
= r^(7-(-7))
= r^14

to get r^6 as an answer the question would have been

r^3 r^-4/(r^-2 r^-5) , and that is not what you typed.

Answer 4

i meant the last problem you typed

Answer 5

in that case, the problem is very straightforward

r^3 r^-4/(r^-2 r^-5)
= r^-1/r^-7
= r^(-1 - (-7))
= r^6