• Brainly User
The elimination method never fails poonam
All the methods are of the same origin.So,If you are not getting a possible answer while doing the elimination method,  Then,You can go for an alternative that is substitution method or cross multiplication method.

Cheers :D
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g honey kon hai...
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[1.2+2.3+.........+n(n+1)]/n(n+3)>= n+1/4, for n>= 1..... prove it
ok g....but mera naam poonam hi hai