几道数学题``我不会做吖```谁会```
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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- 1/5 b)^2 +(a+ 1/5 b)^2 +2b (a-1/25^b)并求值
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- 1/5 b)^2 +(a+ 1/5 b)^2 +2b (a-1/25^b)并求值
![几道数学题``我不会做吖```谁会```](/uploads/image/z/19406718-54-8.jpg?t=%E5%87%A0%E9%81%93%E6%95%B0%E5%AD%A6%E9%A2%98%60%60%E6%88%91%E4%B8%8D%E4%BC%9A%E5%81%9A%E5%90%96%60%60%60%E8%B0%81%E4%BC%9A%60%60%60)
:已知:2^m=x,4^3m=y,要求用x的代数式表示y,则y= x^6
2:已知a+1/a=4,求①a^2+1/a^2②a^4+1/a^4的值
[a+1/a]^2=a^2+1/a^2+2=16
a^2+1/a^2=14
[a^2+1/a^2]^2=a^4+1/a^4+2=196
a^4+1/a^4=194
3:已知:27^2=a^6=9^b,
化简(a- 1/5 b)^2 +(a+ 1/5 b)^2 +2b (a-1/25^b)并求值
27^2=3^6=a^6=3^(2b)
a=3
b=3
上式=2a^2+2/25b^2+2ab-2/25b^2
=2a^2+2ab
=2*3*3+2*3*3=36
2:已知a+1/a=4,求①a^2+1/a^2②a^4+1/a^4的值
[a+1/a]^2=a^2+1/a^2+2=16
a^2+1/a^2=14
[a^2+1/a^2]^2=a^4+1/a^4+2=196
a^4+1/a^4=194
3:已知:27^2=a^6=9^b,
化简(a- 1/5 b)^2 +(a+ 1/5 b)^2 +2b (a-1/25^b)并求值
27^2=3^6=a^6=3^(2b)
a=3
b=3
上式=2a^2+2/25b^2+2ab-2/25b^2
=2a^2+2ab
=2*3*3+2*3*3=36