If you mean the slope is m=-2
I hope this picture helps, but next time try to chose a number to cancel out the fraction. Example, y=1/3x+4 chose 3,6,9 and other multiples of 3.
Jack had b boxes. Then he got 4 more. That is equal to:

On Wednesday, half the boxes were destroyed. To find half the amount, you can divide by 2, which is equal to:

Choice C matches the answer. Your answer is C