Said sometimes the answer is A!
We have the equations:
<span>C(n,k) / C(n,k+1) = 1/2
</span>C(n,k+1) / C(n, k+2) = 2/3<span>
</span>[n! / (n-k)!k! ]/[ <span>n! / (n- (k+1))! (k+1)! ]= 1/2
You can cancel out similar terms. The definition of factorials is this
n! = n(n -1)(n -2)(n -3)...1
So,
</span> (n- (k+1))! (k+1)! / (n-k)!k! = 1/2
(n- k - 1)(n - k - 1 -1)! (k+1)(k + 1 - 1)! / (n-k)!k! = 1/2
(n- k - 1)(n - k - 2)! (k+1)(k)! / (n-k)!k! = 1/2
Cancel out terms.
(n- k - 1)(n - k - 2)! (k+1)/ (n-k)!= 1/2 [eqn 1]
[n! / (n-k+1)!(k+1)! ]/[ n! / (n- (k+2))! (k+2)! ]= 2/3
(n- (k+2))! (k+2)! / (n-(k+1))!(k+1)! = 2/3
(n- k-2)! (k+2)! / (n-k-1)!(k+1)! = 2/3
(n- k-2)(n - k -3)! (k+2)( k+1)k! / (n-k-1)(n-k-2)(n-k-3)!(k+1)k! = 2/3
Cancel out terms
(k+2)/ (n-k-1) = 2/3
You can solve for n in terms of k and substitute this to the fist equation which will allow you to solve for k.
Answer:
x equals to -1
Step-by-step explanation:
x-4x :3
-3x : 3
so x: -1
You need to isolate the variables. For the first equation add x to both sides, which leaves you with y.
For the second equation, divide each side by 2 leaving you with
x= 6+y. Subtract y from each side. Subtract x from both sides. Now you have y= x + 6.
Now graph those equations.
Answer:
The expression equals 50
Step-by-step explanation:
h- 20
Let h = 70
70 -20
50
The expression equals 50