Write (1/3)^7 as 3^x

Write (1/3)^7 as 3^x

With x being the unknown number to find

1/3   = 3^(-1)   so

[3^(-1)] ^7   =  3^(-7)   ......so x = -7

Write (1/9)^2 as 3^y

With y being the unknown number to find

1/9   = 1/3^2   = 3^(-2).....so

[3^(-2)]^2   =    3^(-4) ........so y = -4

Write (1/256)^7 as 4^z

With z being the unknown number to find

1/256  = 1/ 4^4  = 4^(-4)  ....so

[4^(-4)]^7   = 4^(-28)  .......so  z  = -28

Write 81^(7/2) as 4^a

With a being the unknown number to find

Actually...I think it's supposed to be  3^a, not 4^a

81  =  3^4  .......so.....

[3^(4)]^(7/2)   =  3^(28/2) = 3^(14)  ......so a  = 14