Question 565817
The interior angles of a parallelogram add up to 180 deg
4y+x=180

2y+5x-180=180
2y+5x=360


4y+x=180
2y+5x=360 multiply the equation by -2 and to the other equation
-4y-10x=-720

-9x=-540

/-9
x=54  
solve for y

4y+x=180
4y+54=180
4y=136
/4
y=39