Square of (1 + x) + X (1 + x) + X (1 + x) + +What is the sum of the coefficients of all binomial expansions of X (1 + x)

Square of (1 + x) + X (1 + x) + X (1 + x) + +What is the sum of the coefficients of all binomial expansions of X (1 + x)

You didn't write it clearly
The coefficient of binomial, just let x = 1
(1+1)+(1+1)+(1+1)^2+… +(1+1)^n
=2+2+2^2+2^3+.2^n
=2+2+2^2+2^3+.2^n
=2+(1-2^n)/(1-2)
=2^n+1