1. 3y
multiplying 3 and y together gets 3y
2. y-5
5 less implies that we subtract 5 from y
3. y+7
adding 7 to y, self-explanatory
4. 9y
same thing as #1
5. 
quotient of implies division, since number y is listed first, y is the numerator
The first one because the slope is 2/1 and y-intercept is -4
4 ounces are left because 3/4 of 20 is 5. And 1/5 of 5 is 4. I hope this helps