SOLUTION: In the expansion of (1-2x)^11 the coefficient of x^3 is k times the coefficient of x^2. Evaluate k.

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Question 1187143: In the expansion of (1-2x)^11 the coefficient of x^3 is k times the coefficient of x^2. Evaluate k.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
the expansion of the first few terms is 11C0(1^9*(-2x)^0=1
and 11C1(1^10)(-2x)^1=-22x
11C2 (1^9)(-2x)^2=220x^2
11C3(1^6)(-2x)^3=165(-8x^3)=-1320x^3
k=-6, -1320/220