27^x=67 81^y=603 求证:4y-3x-2=2

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/22 13:40:05
27^x=6781^y=603求证:4y-3x-2=227^x=6781^y=603求证:4y-3x-2=227^x=6781^y=603求证:4y-3x-2=2方法1:27^x=673^3x=678

27^x=67 81^y=603 求证:4y-3x-2=2
27^x=67 81^y=603 求证:4y-3x-2=2

27^x=67 81^y=603 求证:4y-3x-2=2
方法1:
27^x=67 3^3x=67
81^y=603 3^4y=603
603/67
=3^4y/3^3x
=3^(4y-3x)
=9=3^2
4y-3x=2
方法2:27^x=67 x=log(27)67
3x=3log(27)67
=3log(3^3)67
=log(3)67
81^y=603 y=log(81)603
4y=4log(81)603
=4log(3^4)603
=log(3)603
4y-3x
=log(3)603-log(3)67
=log(3)(603/67)
=log(3)9
=2 所以4y-3x=2