The coefficient of `x^(7)` in `(1+2x+3x^(2)+..oo)^-5`

Find the coefficient of x^(5) in (1+2x+3x^(2).........

The coefficient of x^(2) in (1)/((1-2x)(1-3x)) is

The coefficient of x^(5) in (1-x-x^(2)+x^(3))^(6) is

Write (i) the coefficient of x^(3) in 3x^(2)-5x^(3)+x^(4) . (ii) the coefficient of x in sqrt(3)-2sqrt(2)x+6x^(2) . (iii) the coefficient of x^(2) in 2x-3+x^(3) , (iv) the coefficient of x in (3)/(8)x^(2)-(2)/(7)x+(1)/(6) . (v) the constant term in (pi)/(2)x^(2)+7x-(2)/(5)pi .

coefficient of x^(5) in (1+x+x^(2)+x^(3))^(10) is

Find the coefficient of x^(5) in (1+2x)^(6)(1-x)^(7)

What is the coefficient of x^(5) in the expansion (1-2x+3x^(2)-4x^(3)+……oo)^(-5) ?