Answer:

Step-by-step explanation:
The complete question in the attached figure
we know that
The <u><em>Triangle Exterior Angle Theorem</em></u> states that: An exterior angle of a triangle is equal to the sum of the opposite interior angles.
In this problem

solve for x

Answer: 2/14; 3/21; 4/28
Step-by-step explanation:
5x + 3y = 460
5(x + y = 120)
5x + 5y = 600
Use elimination subtraction
-2y = -140
y = 70
There are 70 student tickets