Question

How do you factor by grouping `3x^3 y - 9x^3 + 6x^2 y - 18x^2`?

Answer 1

`3x^3y-9x^3+6x^2y-18x^2`

`= color(red)((3x^3y-9x^3)) + color(blue)((6x^2y-18x^2))`

`= color(red)((3x^3)(y-3)) + color(blue)((6x^2)(y-3))`

`=(3x^3+6x^2)(y-3)`

`=(3x^2)(x+2)(y-3)`