please provide step by step to the problem below

2(2r-1)/6+3=3(r+7)/18

I'm taking literally what you wrote which is

2(2r -1)                     3(r + 7 )

______    +   3   =    _______                multiply through by 18  to clear the fractions

     6                             18

3 [ 2(2r -1) ]  +  54  =  3(r + 7 )          simplify

12r - 6   +  54  =  3r +  21

12r + 48  =  3r + 21          subtract   3r, 48 from  both sides

9r  = -27            divide both sides by 9

r  = -3