The slope of AD is the reciprocal of the slope of DC. The slope of BC is the reciprocal of slope BA. The slope of AD is equal to the slope of BC (making those lines parallel). The slope of DC is equal to the slope of Ba (making those lines parallel). I hope this was what you were looking for!
option B is the best it will only lead up to $1.92 while option A is a dollar more
Check the picture below.
make sure your calcualtor is in Degree mode.
Until the end of the problem, pretend the "less-than" sign is an equal sign. What you wanna do is solve for y by getting it by itself. You do this by dividing both sides by 6:
y=18
Because both sides were divided by a positive number, you do NOT flip the sign and leave it as it is:
y<18