5^x+5^(x+1)=750
5^x+5*5^x=750
6*5^x=750
5^x=125
x=3
2^(2x-3)-3*2^(x-2)+1这一个似乎不是方程吧?6*5^x=750 这步是怎么来的？一个5^x加五个5^x等于六个5^x5^x+5*5^x=6*5^x2^(2x-3)-3*2^(x-2)+1=0,你就帮我一起回答这个问题吧！~2^(2x-3)-3*2^(x-2)+1=02*2^(2x-4)-3*2^(x-2)+1=02*2^[2(x-2)]-3*2^(x-2)+1=0 令2^(x-2)=y2*y^2-3y+1=0(2y-1)(y-1)=0y1=1/2 2^(x-2)=1/2 x-2=-1 x1=1y2=1 2^(x-2)=1 x-2=0 x2=2