Answer:
3
Step-by-step explanation:
M is the midpoint of AB. That means that 2 binomials are equal.
4n - 40 = 7* (-2n + 2) Remove the brackets
4n - 40 = - 14n + 14 Add 14n to both sides
4n+14n - 40 = -14n+14n + 14 Combine
18n - 40 = 14 Add 40 to both sides
18n = 14 + 40 Combine
18n = 54 Divide by 18
18n/18 = 54/18 Combine
n = 3
