Radius = 1/2 * diameter = 5
Equation is (x - (-4))^2 + (y - 9)^2 = 5^2
(x + 4)^2 + (y - 9)^2 = 25 is the answer
Let's assume that Kirby walks with a speed

for a time

, and that he runs with a speed

for a time

.
The total time available for Kirby to catch the train is:

and this must be equal to the sum of the two times t1 and t2:
The distance Kirby should cover is

and this should be equal to the sum of the distances covered by walking and by running:

So we have a system of 2 equations:


If we solve the system, we find:


So, Kirby needs to run at least for 8 minutes in order to catch the train.
Answer:
Step-by-step explanation:
Given that four people are on the team. Members will be chosen randomly to serve as chairperson, treasurer, secretary, or timekeeper
Since one person cannot serve two posts we have total number of ways
= 4(3)(2)(1) = 24
If Noor is chair person and Qu treasurer then remaining 2 can take two posts in 2 different ways
So probability that Noor is selected to be chairperson and Qu is selected to be treasurer
=favourable outcomes/total outcomes
= 