Hi there!

The following trapezoidal theorem states that:
Middle segment = average of top and bottom side
Thus:
M = 1/2(b1 + b2)
21 - x = 1/2(17 + 11)
Solve:
21 - x = 1/2(28)
21 - x = 14
Subtract 21 from both sides:
-x = 14 - 21
-x = -7
Multiply both sides by -1:
x = 7
The answer is 0 because 2+5 is 7 and then 5-2 is 7
4 is the answer to the problem
Answer:
second one
Step-by-step explanation:
just multiply by -9 and see which one fits in