How do i find the LCD for the following fractions?

LCD of x² and x + 1
= x²(x + 1)
= x³ + x²

LCD of x and y
= xy

LCD of y³ & y²
= (y)(y)(y)
= y³

LCD of x & x + 1
= x(2)(x + 1)
= 2x(x + 1)
= 2x² + 2x or 2(x² + x)

LCD of x + 1 & x - 1
= (x + 1)(x - 1)
= x² - 1

1)
x + 1 = x + 1
x^2 = x^2
---------------------
The LCD of x + 1 , x^2 is:
x^2(x + 1)
= x^3 + x^2

3/(x + 1) = 3x^2/(x^3 + x^2)
-2/x^2 = (-2x - 2)/(x^3 + x^2)

= = = = = = = =

2)
x = x
y = y
---------------------
The LCD of x , y is:
xy

4/x = 4y/xy
-5/y = -5x/xy

= = = = = = = =

3)
x + 1 = x + 1
x - 1 = x - 1
---------------------
The LCD of x + 1 , x - 1 is:
(x + 1)(x - 1)
= x^2 - 1

2/(x + 1) = (2x - 2)/(x^2 - 1)
3/(x - 1) = (-3x - 3)/(x^2 - 1)

= = = = = = = =

4)
y^3 = y^3
y^2 = y^2
---------------------
The LCD of y^3 , y^2 is:
(y^3)(y^2)
= y^5

3x/y^3 = 3xy^2/y^5
-3x^2/y^2 = -3x^2y^3/y^5

= = = = = = = =

5)
x = x
2(x + 1) = 2(x + 1)
--------------------
The LCD of x , 2(x + 1) is:
2x(x + 1)
= 2x^2 + 2x

1/x = (2x + 2)/(2x^2 + 2x)
1/2(x + 1) = x/(2x^2 + 2x)

**** YOU

X all the denominator together

1) (x+1)x^2
2) xy
3) (x+1)(x-1)
4) y^3
5) 2x(x-1)