In the binomial expansion of (1+ax)^n, where a and n are constants, the coefficient of x is 15. The coefficient of x^2 and of x^3 are equal. What is the value of a and of n?
1 Answer
Nov 26, 2017
Explanation:
The formula for the binomial expansion of
Therefore the
If the
Taking out factors of
which expands to:
We know that
You can check the answer by putting it back into the original formula.