Question

if sum of 'n' natural number is 120 then n=?​

Answer 1

Answer:

n=15

Step-by-step explanation:

n(n+1)/2=120

n square+1=240

split the middle term

n square+n=240

nsquare+16-15n-240=0

n(n+16)-15(n+16)=0

(n+16)(n-15)=n=15