x = 23
Angle H= 39°
Angle I = 118°
Angle J = 23°
The sum of all angles inside a triangle is 180°.
Your equation: (2x -7) + (5x + 3) + x = 180
2x + 5x + x - 7 + 3 = 180
8x - 4 = 180
Your equation in its simplest form:
8x - 4 = 180
Solving for x:
8x - 4 = 180
8x = 184
x = 23
Angle H = 2x - 7
2(23) - 7 = 46 - 7 = 39
Angle I = 5x + 3
5(23) + 3 = 115 + 3 = 118
Checking the math:
39 + 118 + 23 = 180
Please let me know if you have questions.