Question

Use Pascal's Triangle or the Binomial Theorem to find the coefficient on the x³y² term in the expansion of (x − 3 y)⁵.

Type a NUMERIC value only!

Answer 1

Solution:

the coefficient on the x³y² term in the expansion of (x − 3 y)⁵.

The expansion is given by the following formula:

Where

and

We have that a=−3y, b=x, n=5.

Therefore,

Now calculate the coefficient on the x³y²

^{at k=3}

The coefficient of the x³y² is 90.