12x-66=243
12x=243+66
12x=309
x=309/12
x=103/4
97-10x=36
10x=97-36
10x=61
x=61/10
17x-68=136
17x=136+68
17x=204
x=204/17
x=12
24x÷4=9.6
24x=4*9.6
24x=38.4
x=38.4/24
x=1.6
12x-66=243
12x=243+66
12x=309
x=309/12
x=103/4
97-10x=36
10x=97-36
10x=61
x=61/10
17x-68=136
17x=136+68
17x=204
x=204/17
x=12
24x÷4=9.6
24x=4*9.6
24x=38.4
x=38.4/24
x=1.6