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What is the coefficient of x in the expansion of (3x - 4)3 ? |
108 -108 144 -144 |
144 |
Given, (3x – 4)3 (a – b)3 = a3 – b3 – 3ab(a – b) So, (3x – 4)3 = (3x)3 – (4)3 – 3 × 3x × 4(3x – 4) = 27x3 - 64 - 36x(3x – 4) = 27x3 - 64 - 108x2 + 144x So, The coefficient of x in (3x – 4)3 = 144 |
