Find X
I have no idea how to make it

Answer: 5
Step-by-step explanation:
The length of the midsegment is one-half the length of the base. So,
Base = 2(midsegment)
7x + 1 = 2(4x - 2)
7x + 1 = 8x - 4
1 = x - 4
5 = x