Final answer:
To find the least common denominator of two fractions, multiply the denominators together and simplify by common factors.
Step-by-step explanation:
To find the least common denominator of the fractions (4x)/(x-5) and (6)/(x+8), we need to find the least common multiple (LCM) of the denominators (x-5) and (x+8). Since neither denominator is an exact multiple of the other, we can find the LCM by multiplying the two denominators together and simplifying by common factors.
The LCM of (x-5) and (x+8) is (x-5)(x+8). Therefore, the least common denominator of the fractions is (x-5)(x+8).