(1/4.5)+(1/5.6)+(1/6.7)+....+(1/(n+3)(n+4))

Question

(1/4.5)+(1/5.6)+(1/6.7)+....+(1/(n+3)(n+4)) (A) (n/n+ 4) (B) (n/4(n+4)) (C) (n(n+1)/4(n+4)) (D) (n/4(n+3))

Tardigrade Admin · Accepted Answer

Put n = 2. S2 = (1/4.5) + (1/5.6) = (1/12) option (2) = (2/4(2+4)) = (1/12)

Q. $\frac{1}{4.5} + \frac{1}{5.6} + \frac{1}{6.7} + .... + \frac{1}{( n + 3 ) ( n + 4 )}$