Answer:
AD = 13
Step-by-step explanation:
Area of trapezoid ABCD

The mean of the answer is 20.5 because you add all of the number together and divide by 6 because there's 6 numbers.
I'm sorry, but I don't know how to do the standard deviation...
Hope this helped!
I think I could be letter C
Answer:
<u><em>A</em></u>
Step-by-step explanation:
<u>a)</u>
<u></u>
<u></u>
<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
Answer:
16x+16
Explanation:
The perimeter is all of the sides added up. On a rectangle, only 2 sides are needed to know the perimeter because measurements are equal on both sides.
1) Write equation
2*5 + 2(8x+3)
2) Distributive property and multiply
10 + 16x + 6
3) Combine like terms
16x+16