Question

What is the coefficient x^2y^3 in the expression of (2x+y)^5

Answer 1

40

Explanation:

Using nCr, we sub in n=5 and r=2

Then we raise the coefficient of x to the power of 2 and the coefficient of y to the power of 3, and multiply all these together:

`\binom{5}{2}(2)^(2)(1)^(3) = (10)(4) = 40`