1 / 2 bracket 1 / 3 (x-1) - 6 bracket = 1 the process of solving equation

1 / 2 bracket 1 / 3 (x-1) - 6 bracket = 1 the process of solving equation

1/2[1/3(x-1)-6]=1
1/3(x-1)-6=2
x-1-18=6
x=25