Answer:
x =8
The angles are
3x= 24
7x+4 = 60
13x-8 =96
Explanation:
The sum of the angles of the triangle is 180
3x+ 7x+4 + 13x-8 =180
Combine like terms
23x -4 = 180
Add 4 to each side
23x -4+4 =180+4
23x =184
Divide by 23
23x/23 = 184/23
x =8
The angles are
3x= 3*8 =24
7x+4 = 7*8+4 = 56+4 = 60
13x-8 = 13*8-8 =104-8=96