WILL GIVE BRAINLIEST ANSWER TO WHOEVER ANSWERS FIRST AND CORRECT PLEASE EXPLAIN WHY YOU ARE CORRECT

Answer:
A
Step-by-step explanation:
The length of the mid-segment of a trapezoid is equal to half the sum of the lengths of its bases.
(5x-4 + 8x+2)/2 =12
(13x -2)/2 =12
13x-2 = 24
13x =26
x =2