Maths help??

I've tried to attempt this maths question I'm now not sure if it is right.
(Sqrt49)X1/2^-3
I thought it was 7/8 but I just need consolidation and the same for the question below.
(Cube root 8)x4/9^-3/2
Which I thought was 27/8 if these are wrong can u pls describe how to do it but don't give the answer ? Many thanks

For the first one try it again paying attention to the negative power. For the second one you seem to have forgotten about the cube root 8 in the front.

Thank you so much for pointing out my errors I though my answers were a bit strange!

Oh wait I still don't understand the second one I done the cube root of 8 to get 2 then done 4/9^-3/2 to get 27/8. What do I do after that ?

Just multiply 2 and 27/8 together. You've done the hard bit