Solution:
As per the problem we have
WXYZ is an isosceles trapezoid with legs WX and YZ and a base XY.
The length of WX is 6x+5, the length of XY is 10x+4 and the length of YZ is 8x-3.
The diagram representing the above given data has been attached.
Since WXYZ is an isosceles trapezoid with legs WX and YZ.
So we can write

Hence we get x=4