Question

in the expansion of (x-5)^3 the coefficient of x^2 is

please step by step answer
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Answer 1

Answer:

(x-5)³ = x³ - 125 - 3*x*5 ( x - 5)

[ (a-b)³ = a³-b³-3ab(a-b) ]

=> x³ - 125 - 15x² + 75 x²

=> x³ + 60 x²- 125

coefficient of x² = 60