Every quadrilateral will have its interior angles add up to 360.
130 + x + x + 3x = 360
Now combine the like terms,
130 + 5x = 360
Minus 130 to the other side,
5x = 230
Divide both sides by 5 to get x,
x= 46
HOPE THIS HELPED! Ask me if there's any part of the working you don't understand :D
