3^(x+1)*2^x-3^x*2^(x+1)=36
3*3^x*2^x-3^x*2*2^x=36
3^x*2^x=36
6^x=6^2
x=23*3^x*2^x-3^x*2*2^x=36为什么变成3^x*2^x=36