Answer:
x=18 or B
Explanation:
number one is equal to 120 degrees so since the number one and 3x+6 are a straight line it equals 180 degrees
So the equation would be 180=120 + (3x+6)
First you would add like terms
180=126+3x
Then you subtract 126 from both sides to get 3x alone
54=3x
next divide both sides by 3 or multiply by 1/3 to find x
x=18