Question

I need help with this problem need a & b please.

Answer 1

We just have to flip the fraction to transform the exponent into a positive

`((11)/(7))^(-3)=((7)/(11))^3`

Then, we use the power of a division property

`(7^3)/(11^3)=(7*7*7)/(11*11*11)=(343)/(1331)`

Hence, the first power is equal to 343/1331.

We use the same properties for the second power

`(-(5)/(r))^(-3)=(-(r)/(5))^3=-(r* r* r)/(5*5*5)=-(r^3)/(125)`