Question

In the expansion of (1+x)^n, the successive coefficients are a₀, a₁, a₂, a₃,......,aₙ; show that a₀+ 2a₁+ 3a₂+......+(n+1)aₙ = 2^n + n*2^(n-1)

Answer 1

${2}^{n} + {(1 + 1)}^{n - 1}$