(1)28×3+4.5x=93
84+4.5x=93
84+4.5x-84=93-84
4.5x÷4.5=9÷4.5
x=2;
(2)2.6x+1.8=7
2.6x+1.8-1.8=7-1.8
2.6x÷2.6=5.2÷2.6
x=2;
(3)3x-0.86=3.61
3x-0.86+0.86=3.61+0.86
3x÷3=4.47÷3
x=1.49;
(4)x+16=1.4×15
x+16=21
x+16-16=21-16
x=5;
(5)4x-2×3=102
4x-6=102
4x-6+6=102+6
4x÷4=108÷4
x=27;
(6)(x+3)÷2=4.5
(x+3)÷2×2=4.5×2
x+3-3=9-3
x=6.