3(2x-1)=21 6x-3=21 6x=18 x=6
3(2x-1)=21 6x-3=21 /+3 6x=24 /:6 x=4
3(2x-1)=21 6x - 3 = 21 6x= 21 + 3 6x=24 |:6 x=4