The quantities x and y are proportional. x y
2 22
7 77
9 99
Find the constant of proportionality (r) in the equation y=rx

Which of the following is the formula for the sequence graphed below

With these: 18/36 = 1/? missing number change 1 5/8 to improper fraction. change 19/5 to a mixed number.

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?