Answer:
I would say D. There is no logical explanation for the final answer but there is for everything else.
For A: Makes sense because 3x-2 are in parenthesis outside a number so you can multiply.
For B: Makes sense because you are allowed to add/subtract like terms but in this case only subtracting would make sense, (which is what they did) since you want to get all the like terms on one side.
For C: Makes sense because you are trying to simplify the equation, and they are both like terms (they are both numbers that have no letter attached to them) and they are on the opposite side making them able to be simplified.
For D: No idea what the point is.
The unit rate is $8/hr and the equation for y would be y=2x. The slope would be 8
The answer is 180 because 6 x 3=18 and 18x10=180
If the two diagonals are
and
, the are of the rhombus is

So, in your case, the area is

The other options are wrong because:
- option A doens't divide by 2, thus getting twice the area of the rhombus
- option B summed the diagonals instead of multiplying them
- option D took the difference of the diagonals.