Question

Please help me!!!!!!!!!!!!

Answer 1

1215

Explanation:

Using the Binomial theorem

With coefficients obtained from Pascal's triangle for n = 6, that is

1 6 15 20 15 6 1

and the term 3x decreasing from
`(3x)^(6)` to
`(3x)^(0)`

and the term - y increasing from (
`(-y)^(0)` to
`(- y)^(6)`

Thus

`(3x-y)^(6)`

= 1 ×
`(3x)^(6)`
`(-y)^(0)` + 6 ×
`(3x)^(5)`
`(-y)^(1)` + 15 ×
`(3x)^(4)`
`(-y)^(2)` + .........

The term required is

15 ×
`(3x)^(4)`
`(-y)^(2)`

= 15 × 81
`x^(4)` y²

with coefficient 15 × 81 = 1215

that is 1215
`x^(4)`y²