You can put this solution on YOUR website! 6(d+6) = 4(d-6)+2d
You are going to use the DISTRIBUTIVE PROPERTY here.
So apply the 6 to the d and the 6. 6(d+6) = 6d + 36.
So....
6d + 36 = 4(d-6) + 2d
6d + 36 = 4d -24 + 2d
6d + 36 = 6d -24
36 = -24.
Since this is not true, you have no solution for d.