If two consecutive terms in the expansion of (x+a)ⁿ are equal where n is a positive integer then (n+1)a/x+a is

If the sum of odd terms and the sum of even terms in the expansion of (x+a)ⁿ are p and q respectively then p²+q²=

If the coefficients of (2r+1)^th term and (4r+5)^th term in the expansion of (1+x)¹⁰ are equal then r=

If the 3^rd, 4^th and 5^th terms of (x+a)ⁿ are 720, 1080 and 810 respectively then (x,a,n)=

xⁿ-1 is divisible by x-k. Then the least +ve integral value of K is