W) {(8, 9), (2, 3), (0, -2), (10, -9)}
x) {(0, 0), (5, 10), (-3, 3)}
y) {(1, 1), (2, 2), (3, 3), (4, 4)}
z) {(-10, 1), (-9, 3), (-4, 5)}
which of the sets represent functions?

a. w, x
b. x, y,z
c. w, z
d. w, x,y, z

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?

Write the function for the graph. (1.8) (0,4)