Sum of first n natural no. Is S ans S=n(n+1)/2. If S=55 then find value of n. About the author Nevaeh
Answer: 10 Step-by-step explanation: S= n/2+(2a+(n-1)d) 55= n/2 + (2 + (n-1)) 110= 2n-n+n² n²+n-110=0 n²+11n-10n-110=0 n(n+11) -10(n+11)=0 n= 10, -11 n≠ -11 so the value of n is 10 Reply
Step-by-step explanation: 55=n(n+1)/2 110=n²+n n²+n-110=0 n²+11n-10n-110=0 n(n+11)-10(n+11)=0 n=10 Reply
Answer:
10
Step-by-step explanation:
S= n/2+(2a+(n-1)d)
55= n/2 + (2 + (n-1))
110= 2n-n+n²
n²+n-110=0
n²+11n-10n-110=0
n(n+11) -10(n+11)=0
n= 10, -11
n≠ -11
so the value of n is 10
Step-by-step explanation:
55=n(n+1)/2
110=n²+n
n²+n-110=0
n²+11n-10n-110=0
n(n+11)-10(n+11)=0
n=10