两边除以6^x
2×(9/6)^x-5+3×(4/6)^x=0
2×(3/2)^x-5+3×(2/3)^x=0
令a=(3/2)^x
则(2/3)^x=1/a
所以2a-5+3/a=0
2a²-5a+3=0
(2a-3)(a-1)=0
a=3/2,a=1
(3/2)^x=a=3/2
x=1
(3/2)^x=a=1
x=0
综上
x=1,x=0
3*2的2x次方+2*3的2x次方-5*6的x次方=0
可以化为:3*4^x+2*9^x-5*6^x=0,两边同除以6^x可得:
3(2/3)^x+2*(3/2)^x-5=0, 令t=(3/2)^x, 则(2/3)^x=1/t,
从而将上式化为:3/t+2t-5=0
2t^2-5t+3=0
解得t=1,3/2.
所以(3/2)^x=1,3/2
x=0,1.