Question 47753
LCD of 9x-63 and 12x-84.

Factor each denominator as follows:
3^2(x-7) and 3*2^2(x-7)

The LCD is the product of the highest power of each of these prime factors:
LCD=3^2 * 2^2 * (x-7)= 36(x-7)

Cheers,
Stan H.