find the value of x and y that make the quadrilateral

The quadrilateral have equal opposite sides, for example:
Then, (4x + 6) must be equal to (7x - 3), and (4y - 3) is equal to (3y + 1), therefore
[tex]4x+6=7x-3[/tex]We can solve that equation for x
[tex]\begin{gathered} 4x+6=7x-3 \\ \\ 3x=9 \\ \\ x=\frac{9}{3}=3 \end{gathered}[/tex]Hence, x = 3. Now let's solve the other equation
[tex]\begin{gathered} 4y-3=3y+1 \\ \\ y=4 \end{gathered}[/tex]Then the value of y is 4.
Final answers:
x = 3
y = 4