The area of a rectangular patio is (12x - 4) square units. what are possible dimensions of the patio?

You need two terms that multiply to (12x-4). The term on the outside needs to be a common multiple of 12 and 4. The common factors are 1, 2, and 4. Here are the following possible dimensions:
1(12x-4)
2(6x-2)
4(3x-1)
Hope this helps. 

A.  The difference of the two means is significant, so the null hypothesis must be rejected.

B.  The difference of the two means is significant, so the null hypothesis must be accepted.

C.  THE DIFFERENCE OF THE TWO MEANS IS NOT SIGNIFICANT, SO THE NULL HYPOTHESIS MUST BE REJECTED.

D.  The difference of the two means is not significant, so the null hypothesis must be accepted.