Respuesta :

Answer:

x=10

Step-by-step explanation:

By the Trapezoid Midsegment Theorem, the midsegment of a Trapezoid is 1/2(the sum of the 2 bases.

4x-20=1/2(23+17)

4x-20=1/2(40)

4x-20=20

4x=40

x=10