Answer:12
Step-by-step explanation:
Sum of angles on a straight line=180
10x - 20+6x + 8=180
Collect like terms
10x + 6x + 8 - 20=180
16x - 12 = 180
Add 12 to both sides
16x - 12+12=180+12
16x=192
Divide both sides by 16
16x/16=192/16
X=12
