x2+x+2 is not factorable using rational numbers. This means that no rational numbers added together equal 1 (x in equation) and multiplied together equal 2.
You can find the imaginary answer to x2+x+2=0 (an equation, notice the =), however.
Using the quadratic formula: −b±√b2−4ac2a
x would then equal −1±i√72
and the factors would be x2+x+2=(x+1+√7i2)(x+1−√7i2)