How do you simplify (x - y)^3(xy)3?

1 Answer
Jul 14, 2017

x^3 - 3x^2y + 3xy^2-y^3x33x2y+3xy2y3

Explanation:

(x - y)^3(xy)3

Solution

Well you can use many methods to simplify like:

Using Pascal Triangle which give be 1, 3, 3, 11,3,3,1 as the expansion..

You can simplify (x - y)^3(xy)3 to either (x - y) (x - y) (x - y) or (x - y)^2 (x - y)(xy)(xy)(xy)or(xy)2(xy)

But using those two will result in same answer which will be in this format -> 1, 3, 3, 11,3,3,1

Hence rArr (x - y)^3 = (x - y) (x - y) (x - y)(xy)3=(xy)(xy)(xy)

(x - y) (x - y) (x - y)(xy)(xy)(xy)

(x - y) [(x - y) (x - y)](xy)[(xy)(xy)]

(x - y) [x^2 - xy - xy + y^2](xy)[x2xyxy+y2]

This lead to the point using difference of two cubes as:

(x - y) [x^2 - 2xy + y^2](xy)[x22xy+y2]

x [x^2 - 2xy + y^2] - y [x^2 - 2xy + y^2]x[x22xy+y2]y[x22xy+y2]

x^3 - 2x^2y + xy^2 - x^2y + 2xy^2 - y^3x32x2y+xy2x2y+2xy2y3

Collect like terms

color(red)(x^3 - y^3) color(blue)(- 2x^2y - x^2y) color(green)(+ xy^2 + 2xy^2) x3y32x2yx2y+xy2+2xy2

:. x^3 - y^3 - 3x^2y + 3xy^2 -> Answer

If it is the cube of a binomial, it will be in this format rArr color(red)(1)x^3 - color(red)(3)x^2y + color(red)(3)xy^2 - color(red)(1)y^3