(1)3x+x-6=26
4x-6=26
4x-6+6=26+6
4x÷4=32÷4
x=8;
(2)
:x=3 5
:7 9
7 12
x=7 9
×3 5
7 12
x÷7 9
=7 9
÷7 20
7 9
x=
; 9 20
(3)1.3x+4.7x+x=60.2
7x=60.2
7x÷7=60.2÷7
x=8.6.