Solving rational inequalities and use sign diagram to sketch the graph. image attached for better understanding.

x ∈ (-∞ , -2) ∪ (1, 3)

Step-by-step explanation:

The expression is already factored. Note that for the polynomial that appears in the numerator there are 2 roots:

For the polynomial that appears in the denominator there is 1 root:

Note that does not belong to the domain of f(x) because it zeroes the denominator of the function and the division between zero is not defined.

With these three roots we do the study of signs to find out when

Observe the attached image

Note that:

when

when

when

Finally, we have the solution:

x ∈ (-∞ , -2) ∪ (1, 3)

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490