jawab dan pakai cara...

Diketabui sudut berpelurus
=180°
maka
2x+8+2x-20= 180
2x+2x=180+20
4x=200
x=200/4
x=50

2x + 8 + 2x - 20 = 180
2x + 2x + 8 - 20 = 180
4x - 12 = 180
4x = 180 + 12
4x = 192
x = 192 : 4
x = 48