Volume= Length * width ( aka Base ) * height
Break up the figure into easier figures, a small square and a bigger square.
Small square- 3*2*1 = 6 cm
Large Square- 7*6*1 = 42 cm
42 + 6 = 48 cm. But wait! You have to take one more step, which is minus-ing 6 from 48. Why? Notice that there is a little area where a side of the small square meets the bigger square. That little area is worth 3 cm ( length is 3, height is 1 cm ) times 2 ( 3 cm is one side, another 3 cm is the other side from the other square ) = 6 cm.
Your total answer should be 42. ( or 48, if your teacher doesn't count the area where the squares meet/join together ).
X 0 y was 30
at x 12 y is about 55
12-0 = 12
55-30 = 25
25/12 = 2.08 inches per year average
so answer should be D
I believe you are right with all of them.
The first reaction represented is a decomposition reaction due to the fact the bonded pair are being split apart.
The second equation is a single displacement because the B and C have switched places, which is the only change making it a single displacement. If there had been another bond and A had also moved, it would be double.