The LCM of
and
is (x+9)(x−9)(x−3), which matches option 4: (x+9)(x−9)(x−3).
To find the LCM (Least Common Multiple) of the polynomials
and
, let's factorize these polynomials first:
can be factorized using the difference of squares formula:

factors as a perfect square trinomial:

Now, to find the LCM, we need to consider each factor and take the maximum power for each unique factor.
The factors in
are (x+9) and (x−9).
The factors in
are (x−3) and (x−9).
The LCM will contain each unique factor raised to its highest power:
x+9 appears in both factorizations, so its highest power is x+9.
x−9 appears in both factorizations, so its highest power is x−9.
x−3 appears only in the factorization of
, so it remains as x−3.
Therefore, the LCM of
and
is (x+9)(x−9)(x−3), which matches option 4: (x+9)(x−9)(x−3).
Question
Find the LCM of (x^2-81) and(x^2-12x+27)
1. (x - 9)
2. (x − 3) (x -9)
3. (x + 9) (x − 9) (x+3)
4. (x + 9) (x − 9) (x-3)