Answer:
all real numbers except the number 2 and number 1
Explanation:
we have

we know that
In a quotient, the denominator cannot be equal to zero
so

Solve for x
The values of x are
x=2, x=1
so
The domain of the function is all real numbers except the number 2 and number 1
In interval notation
(-∞,1) ∩ (1,2) ∩ (2,∞)