STEP - BY - STEP EXPLANATION
What to find?
The factor of x² + 9
Observe from the expression above, the sign between the two term is positive.
If it were a negative, then we can easily apply the principle of difference of two square which will be
But since the expression given is with a positive sign, then it is not factorable with any rational numbers.
ANSWER
x² + 9 is not factorable with any rational numbers.