Find the lowest common multiple of 3 and 5, that is 15
the lights will blink together every 15 seconds
in 1 minute blink together 
= 4 times
that is at 15, 30, 45 and 60
Setting f(x) = 0, we have:
-x2 -7x +30 =0
The roots of this quadratic equation are:
x = 3 and -10
Since the diver is on a diving board, the -10 is somewhere behind him. We use the root x = 3 since this distance is in front of the board.
Therefore, the answer is:
x = 3; the diver hits the water 3 feet away horizontally from the board
PS = PR + RS = 4x - 2 + 3x - 5 = 7x - 7.
Chuck will be able to draw a cylinder in the polyhedron because he has a pair of the congruent bases. He may draw circle on the bases and connect the whole circumference of the circle at top and the whole circumference of the circle at the bottom to form the cylinder.
The y values decrease as the x values increase. If you picture the points in your head, you’ll see that (2,2) is to the right and lower than (-3,5), creating a negative slope.
