Find the positive integer n such that the expansion of (4x - 7y)^n contains a term of the form cx^2*y.

Guest Mar 19, 2023

#1**0 **

The answer is 3.

This is because if one **term** is in the form of an x^2, the lowest power needs to be 2. However, since we also have a *y*, we know the equation can't be a quadratic (think it through!), and therefore the only power sufficing this form would be 3.

Does that make sense?

Guest Mar 20, 2023