Answer:
<u><em>A</em></u>
Step-by-step explanation:
<u>a)</u>
<u></u>
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<u>8(9) / 9 = 8 x 7 = 56</u>
b)

2(9) * 3 - 12
18 * 3 = 54 - 12 = 42
c)

4(9) - 18 + 12
36 - 18 = 18 + 12 = 30
d)

21 + 24 = 45
In order to find the area, you multiply the width (7), height (6) and length (12). But the problem states that the height has changed from 6 to 6 minus3, which would be 3. So you multiply 3, 7, and 12.
About 29%.
35 - 25 = 10, or the amount of change
10 / 35 = .285, or the amount of change over total