几道数学题``我不会做吖```谁会```
1:已知:2^m=x,4^3m=y,要求用x的代数式表示y,则y=
2:已知a+1/a=4,求①a^2+1/a^2②a^4+1/a^4的值
3:已知:27^2=a^6=9^b,
化简(a-1/5b)^2+(a+1/5b)^2+2b(a-1/25^b)并求值