解:7-2[3[4(x-1)-8]-20]=1
7-1=2[3[4(x-1)-8]-20]
2[3[4(x-1)-8]-20]=6
3[4(x-1)-8]-20=3
3[4(x-1)-8]=23
4(x-1)-8=23/3
4(x-1)=23/3+8=47/3
x-1=47/12
x=47/12+1=59/12
2[3[4(x-1)-8]-20]=7-1
3[4(x-1)-8]-20]=6/2
[4(x-1)-8]-20=3/3
4(x-1)-8=1+20
4(x-1)=21+8
x-1=29/4
x=33/4