1-x+y/x=

1 - x-y/x+y=

1/x+y+1/x-y=

2/y-x-1/x-y=

a/a-b-a+b/a-b=

a/a-b-a+b/b-a=

a/a-b+a+b/2a-2b=

a/a-b+ab / (a-b) во 2 степени=

a/a-b-a-b/a=

1-y+x/x = x-x+y/x = y/x

1-x-y/x+y = x+y/x+y - x-y/x+y = 0

1/x+y+1/x-y = x-y+x+y/x^2-y^2 = 0

2/y-x-1/x-y=-2/x-y - 1/x-y=-3/x-y

a/a-b-a+b/a-b=a-a+b/a-b = b/a-b

a/a-b-a+b/b-a=-a/b-a-a+b/b-a = - 2a+b/b-a

a/a-b+a+b/2a-2b=2a/2 (a-b) + a+b/2 (a-b) = 3a+b/2 (a-b)

a/a-b+ab / (a-b) во 2 степени=a (a-b) + ab / (a-b) ^2 = a^2-ab+ab / (a-b) ^2 = a^2 / (a-b) ^2

a/a-b-a-b/a=a^2-a^2-2ab+b^2/a^2-ab = - 2ab+b^2/a (a-b) = b (2a+b) / a (a-b)

^2 - это значит во второй степени