Преобразуйте выражения:

1.

3x+y - x = 3x+y - x = x (3x+y) - x (x+y) = x (3x+y-x-y) =

x²-y² x²-xy (x-y) (x+y) x (x-y) x (x-y) (x+y) x (x-y) (x+y)

= 2x = 2x

(x-y) (x+y) x²-y²

2.

y+a + y-b = y+a + y-b = a (y+a) + b (y-b) =

b²+ab a²+ab b (b+a) a (a+b) ab (a+b)

=ay+a²+by-b² = (a²-b²) + (ay+by) = (a-b) (a+b) + y (a+b) =

ab (a+b) ab (a+b) ab (a+b)

= (a+b) (a-b+y) = a-b+y

ab (a+b) ab