We know by property that∑axⁿ + bx^{n - 1} + cx^{n - 2}…….d₀=a∑xⁿ + b∑x^{n - 1} + c∑x^{n - 2}…….. + d₀∑1

We know

(1)

(2)

(3)

Adding (1) (2) and (3)

=