<u><em>Answer:</em></u>x = 7
MN (first base) = 17 units
OP (second base) = 21 units
QR (median) = 19 units
<u><em>Explanation:</em></u>In a trapezium, the length of the median is equal to half the sum of the two bases.
<u>From the given, we have:</u>
MN (first base) = 17 units
OP (second base) = 5x - 14 units
QR (median) = x + 12 units
<u>Applying the above rule:</u>
median = 0.5 (first base + second base)
x + 12 = 0.5 (17+5x-14)
2(x+12) = 17+5x-14
2x + 24 = 3 + 5x
24-3 = 5x-2x
21 = 3x
x =

x = 7
<u>Based on the above, the lengths would be:</u>
MN (first base) = 17 units
OP (second base) = 5x - 14 = 5(7) - 14 = 21 units
QR (median) = x + 12 = 7 + 12 = 19 units
Hope this helps :)