0 because the number in the middle is the midpoint.
Answer:

Step-by-step explanation:
Hello!
The expression is written in the form of 
Let's factor by grouping:

The sum of the factors of -50 should add up to -23.
-25 and 2 work for this.
Expand and factor:
The factored expression is 
For number 7 what is the formula for volume of a cube
Do 110 times 40 to get 440 you are welcome hope u are good