Answer:
x = 25
Step-by-step explanation:
The sum of the angles of a quadrilateral are 360 degrees
3x+x+10 + 4x+6x = 360
Combine like terms
14x+10 = 360
Subtract 10 from each side
14x +10-10 = 360-10
14x = 350
Divide each side by 14
14x/14 = 350/14
x = 25
