Question

Find the coefficient of Y^2 in the expansion of (2x+y)^3

Answer 1

Explanation:

`\text{Use}\ (a+b)^3=a^3+3a^2b+3ab^2+b^3.\\\\\text{We have}\ (2x+y)^3\\\\=(2x)^3+3(2x)^2(y)+3(2x)(y^2)+y^3\\\\\text{The coefficient of}\ y^2\ \text{is}\ (3)(2)=6`