Question

How do you factor completely `3x^3y - 48xy^3`?

Answer 1

`3xy(x-4y)*(x+4y)`

Explanation:

`3x^3y - 48xy^3`

Taking 3xy common in the above expression, we get,
`3xy(x^2-16y^2)`
`=3xy(x^2-(4y)^2)`

Now, since
`(a^2-b^2) = (a-b)*(a+b)`

the above expression reduces to
`3xy(x-4y)*(x+4y)`