The coefficient of x2 in (2x + y)3 is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 12y.
| Understanding/Application |
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(a + b)3 = a3 + b3 + 3ab(a + b) (2x + y)3 = (2x)3 + y3 + 3.2x.y(2x + y) = 8x3 + y3 + 6xy(2x + y) |
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= 8x3 + y3 + 12x2y + 6xy2 Thus, the coefficient of x2 = 12y |