Answer:
x = 10, AB = 57
Step-by-step explanation:
In a trapezoid, the length of the median is one-half the sum of the lengths of the bases. From this, we have:
[tex] \frac{1}{2} (5x + 7 + 8x - 11) = 63[/tex]
[tex]13x - 4 = 126[/tex]
[tex]13x = 130[/tex]
[tex]x = 10[/tex]
[tex]5(10) + 7 = 50 + 7 = 57[/tex]
