if 2n+1 pn-1, 2n-1 pn = 3.5 , find the value of n
Answers
Answered by
1
Answer:
4
Step-by-step explanation:
Given equation is
2n+1
P
n−1
:
2n−1
P
n
=3:5
So,
(2n−1−n)!
(2n−1)!
(2n+1−n+1)!
(2n+1)!
=
5
3
⇒
(n+2)(n+1)n(n−1)!
(2n+1)(2n)(2n−1)!
×
(2n−1)!
(n−1)!
=
5
3
Solving we get
⇒
(n+1)(n+2)
2(2n+1)
=
5
3
⇒20n+10=3n
2
+9n+6
⇒3n
2
−11n−4=0
⇒3n
2
−12n+n−4=0
⇒3n(n−4)+1(n−4)=0
∴n=4
Answered by
0
Answer:
2n+1 pn-1, 2n-1 pn=3.5
Step-by-step explanation:
easy first
find common numbers
like
(2n)²-(1)²pn= 3.5
=4n-1pn= 3.5
transpose p to right side
4n-1n= 3.5p
3n=3.5p
n=3.5/3× p
Similar questions