Answer
0.22580645161
Step-by-step explanation:
you just have to do 4 3/7 in a calculator
~For this problem, you need to divide.
~The easy way that I think might help you is if you change the fraction into a decimal.
Now divide $8.47 by 0.875
The price per pound of the coffee was $9.68
It's hard to type and hard to read the "inverse tangent" function, as you've seen (above).
So, use "arctan x" instead.
Then the problem becomes: "differentiate cos (arctan x)."
You must apply first the rule for differentiating the cosine function, and next apply the rule for differentiating the arctan function:
(d/dx) cos (arctan x) = - sin (arctan x) * [1/(1+x^2)]
Hope this helps!! Solved it step by step:)
Answer:
Proof for 
Step-by-step explanation:
We are given that a, n, b, r and k are integers.
Also,

Since k divides a and b, we can write,
a = rk and b = sk, where r and s are integers.
Now, we have to prove that k divides r as well that is 
Putting value of a and b in the equation, we get:

Since, (r-sn) is an integer, k divides r.