1)Simplify x−1+y−1x+y
2)Simplify x−1−y−1x−y
3)Simplify x−2+y−2x+y
4)Simplify x−2−y−2x−y
These questions are 'created' by my teacher, I find this kind of funny and want to share this to you!! :D
I would like you to share your answers to these questions.
I will go first :)
1) x−1+y−1x+y=(x−1+y−1)(xy)(x+y)(xy)=y+x(x+y)(xy)=1xy
2)x−1−y−1x−y=(x−1−y−1)(xy)(x−y)(xy)=−(x−y)(x−y)(xy)=−1xy
3)x−2+y−2x+y=1x2+1y2x+y=x2+y2(xy)2x+y=x2+y2(xy)2(x+y)
4)x−2−y−2x−y=(x−1+y−1)(x−1−y−1)x−y=x−1−y−1x−y(x−1+y−1)=−x−1+y−1xy
The last step of 4) is from 2)!!