已知3x=4,3y=6,求92x-y+27x-y.
问题描述:
已知3x=4,3y=6,求92x-y+27x-y.
答
92x-y+27x-y=92x÷9y+27x÷27y
=(3x)4÷(3y)2+(3x)3÷(3y)3
=44÷62+43÷63
=
+64 9
8 27
=
+192 27
8 27
=
.200 27