Find the LCD of the ration expressions:

A) [9x/(x^2-z^2)] [3/(x^2-2xz+z^2)]

B) [x/(x^2-64)] [2/(40-5x)] [7/x]

A. Factors of denominators:

(x^2-z^2) = (x+z)(x-z)
(x^2-2xz+z^2) = (x-z)(x-z)
Thus, LCD : (x+z)(x-z)(x-z)

B. Factors of denominators:
(x^2-64) = (x-8)(x+8)
(40-5x) = -5(x-8)
x = x
Thus LCD : -5x(x-8)(x+8)

Hope this helps :3