I believe it's B.
If I'm wrong tell me so I can see what I did wrong.
Answer:

Step-by-step explanation:
<em>Look at the picture.</em>
We have
square with side length a = 9
trapezoid with base lengths b₁ = 9 and b₂ = 6 and the height length h = 6
right triangle with legs lengths l₁ = 3 + 6 = 9 and l₂ = 6
The formula of an area of a square

Substitute:

The formula of an area of a trapezoid:

Substitute:

The formula of an area of a right triangle:

Substitute:

The area of the shape:

Answer:
-8m + 3 - 32n
Step-by-step explanation:
Distributive Property
-8m + 3 - 32n
<u>Answer:</u>
B. He multiplied the dividend by 100 instead of 10.
<u>Step-by-step explanation:</u>
Chen had to divide
by
. To make it easier to divide, he thought of multiplying both the dividend and the divisor by 10.
Chen multiplied the divisor by 10 but mistakenly multiplied the dividend by 100 instead of 10.
So his whole division problem was changed.
Therefore, the correct answer option is B. He multiplied the dividend by 100 instead of 10.