Answer:
The median of a trapezoid is equal to one-half the sum of its bases.
[tex]m=\frac{1}{2} (b_{1} +b_{2} )[/tex] or [tex]2m=b_{1} +b_{2}[/tex]
Applying this to problem,
[tex]2(6x-18)=(5x+7)+(3x+1)[/tex]
[tex]12x-36=8x+8[/tex]
[tex]12x-8x=8+36[/tex]
[tex]4x=44[/tex]
[tex]x=11[/tex]
