How do you simplify (x + y)(x - y)(x+y)(xy)?

1 Answer
Jul 22, 2016

(x+y)(x-y)=x^2-y^2(x+y)(xy)=x2y2

Explanation:

To simplify (x+y)(x-y)(x+y)(xy) we use distributive property of number systems.

Let us treat (x+y)(x+y) as a single number and distribute it over (x-y)(xy).

This makes (x+y)(x-y)(x+y)(xy)

= (x+y)x-(x+y)y(x+y)x(x+y)y

Now using commutative property of multiplication the above is equivalent to

x(x+y)-y(x+y)x(x+y)y(x+y) and now again using distributive property this is equivalent to

x xx x+x xx y- y xx x-yxxyx×x+x×yy×xy×y

x xx x+x xx y- x xx y-yxxyx×x+x×yx×yy×y

= x^2+xy-xy-y^2x2+xyxyy2

= x^2+cancel(xy)-cancel(xy)-y^2

= x^2-y^2