Answer:
x = 20
Explanation:
Assuming you require the value of x
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
7x - 15 is an exterior angle of the triangle, thus
7x - 15 = x + 28 + 4x - 3 , that is
7x - 15 = 5x + 25 ( subtract 5x from both sides )
2x - 15 = 25 ( add 15 to both sides )
2x = 40 ( divide both sides by 2 )
x = 20