(1)x÷0.4=11
x÷0.4×0.4=11×0.4
x=4.4;
(2)8.2-
x=43 5
8.2-
x+3 5
x=4+3 5
x3 5
8.2-4=4+
x-43 5
4.2÷
=3 5
x÷3 5
3 5
x=7;
(3)10+4x=15
10+4x-10=15-10
4x÷4=5÷4
x=1.25;
(4)x-15%x=68
85%x=68
85%x÷85%=68÷85%
x=80;
(5)3(x-1)=9
3(x-1)÷3=9÷3
x-1+1=3+1
x=4;
(6)0.5x+6=18
0.5x+6-6=18-6
0.5x÷0.5=12÷0.5
x=24.