The Answer for this Question would be D
EXPLICATION:
The reason this is the answer as 7 raised to the power of 2 is 7 Times 7 which equals 49. If you use the distribution method for 3(4+6) if you add 4+6 = 30; 3(10) = 30; then you have -2 so 30-2= 28.
So the final answer would be 28 x 49
