Answer:
x = 48
Step-by-step explanation:
first you would add them together and set it equal to 180( because a straight line is 180 degrees): 3x - 12 + x = 180
Then you add like terms( the x's): 4x - 12 = 180
now add 12 to both sides: 4x = 192
now divide by 4 on both sides x = 48
hope this helps! : )
