Answer:
x=8
Explanation:
Since it is an isosceles trapezium, we know that GF and DE are parallel, and that EF = GD. Since we know that co-interior angles always add up to 180 degrees, we know that:
Angle F (13x+4) + Angle E (9x) = 180
So we can write an equation for x and solve it.
13x+4+9x=180
22x + 4 = 180
22x + 4 - 4 = 180 - 4
22x = 176
22x/22 = 176/22
x = 8
Hope this helped!