The answer is D. 42
A triangle equals 180 in total so what you would do it subtract 122 from 180 because 180 is also the angle of a straight line. You would get 58 then you add 58 and 80 to get 138. Subtract 138 from 180 and you get your answer of 42
8 is the missing number
Let’s say x is 2,
3(2)+8=14
8(2)-2=14
The new price would be $19.99
29.99 x .6666 = $19.99
(Old price multiplied by discount percentage = new price)

Two lines are parallel when their slopes are the same.
Step-by-step explanation:
2(2x + 1) = 3(x - 4)
4x+2=3x-12
4x-3x=--12-2
x=14