`sum_(r=1)^6 6C_r`

sum_(r=0)^6 .^(6)C_(r) xx ^(6)C_(6-r) = ?

Find the value of :^50C_4+sum_(r=1)^6 .^(56-r)C_3.

The number of solutions of sum_(r=1)^6 cos(rx)=6 in

Given a sequence t_1 , t_2 ,..... if its possible to find a function f(r) such that t_r = f(r + 1) - f(r) then sum_(r = 1)^n t_r = f(n + 1) - f(1) Sum of the sum_(r = 1)^n r(r + 3)(r + 6) is

If C_(r)=10C_(r), then sum_(r=1)^(10)C_(r-1)C_(r) is equal to

Find sum_(r=1)^n ( 6r^2 + 4r - 3)

Let sum_(r=1)^(n) r^(6)=f(n)," then "sum_(n=1)^(n) (2r-1)^(6) is equal to

Let sum_(r=1)^(n) r^(6)=f(n)," then "sum_(n=1)^(n) (2r-1)^(6) is equal to