We have 4 x's and 2 "units" in the left side. We know that this is equal or equivalent to one X and 8 units, pictured in the right side.
So we can write the left side as: 4x+2
And the rigth side as: x+8
As both sides are equal, we can write:
[tex]4x+2=x+8[/tex]
The answer is Option D: 4x+2=x+8
