Respuesta :

We know that the opposite angles are equal
So...

3y - 20 = 2x + 6    and    4x = 4y + 4

That is the system of equations you need to solve
for the figure to be a parallelogram, opposite angles need to be congruent

that means B = D and A = C

thus [tex]\bf \begin{cases} 3y-20=2x+6\\ -2x+3y=26\\ ----------\\ 4x=4y+4\\ 4x-4y=4\\ x-y=1 \end{cases}\implies \begin{cases} -2x+3y=26\\ x-y=1 \end{cases}[/tex]