Answer:
c
Step-by-step explanation:
The median is half the sum of the parallel bases, that is
UV = [tex]\frac{BC+AD}{2}[/tex]
3 + 20x = [tex]\frac{13+31x+2}{2}[/tex] ( multiply both sides by 2 to clear the fraction )
6 + 40x = 15 + 31x ( subtract 31x from both sides )
6 + 9x = 15 ( subtract 6 from both sides )
9x = 9 ( divide both sides by 9 )
x = 1
Then
UV = 3 + 20x = 3 + 20(1) = 3 + 20 = 23 → c
