Two puppies which are 520 feet apart are running towards each other. their speeds are 4 and 5 feet per second. how much time will elapse before they are 250 feet apart from each other?

your constant k is k=-2C2/(4π)2

Step-by-step explanation: this should help with your problem: I think that the problem you are having is that you have carried the minus sign into your constant. But that minus sign is important because it tells you (since everything else in k is constant) that the radius of the surface is increasing, but the rate at which it is increasing is decreasing as r changes. So, if the volume of a sphere is increasing with a constant rate, its radius is increasing like 1/r2, but the rate at which the speed of the surface is decreasing goes like 1/r5.

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9