f.4 binomial

[(1+1/x)^2] (2-x)^7
= (1 + 2/x + 1/x^2)[2^7 + 7(-x)(2)^6 + 21[(-x)^2](2)^5 + 35 [(-x)^3](2)^4 + ...]
= (1 + 2/x + 1/x^2)(128 - 448x + 672x^2 - 560x^3 + ...]

Therefore, coefficient of x
= (1)(-448) + (2)(672) + 1(-560)
= 336

(1+1/x)^2 = 1 + 2(1/x) + (1/x)^2
(2-x)^7 = 2^7 + (7)(2^6)(-x) + (21)(2^5)(-x)^2 + ......

coefficient of the binomial
= (1)(2^7) + (7)(2^6)(-1)(2) + (21)(2^5)(1)
= -96