已知2的x次方等于a,2的y次方等于b,求2x-y的次方+2的3x+2y的次方的值,

问题描述:

已知2的x次方等于a,2的y次方等于b,求2x-y的次方+2的3x+2y的次方的值,

2的x-y的次方+2的3x+2y的次方
=2^x÷2^y+(2^x)³(2^y)²
=a/b+a³b²

2x-y的次方+2的3x+2y的次方
=2的x次方÷2的y次方+(2的x次方)³×(2的y次方)²
=a/b+a³b²

2^x=a
2^y=b
2^(x-y)+2^(3x+2y)
=2^x÷2^y+(2^x)^3(2^y)^2
=a/b+a³b²
=(a+a³b³)/b