Answer:
(9x +1)(x +1)
Step-by-step explanation:
The numbers in the binomial factors are factors of 9·1 that have a sum of 10. The factors 9 and 1 are such numbers.
One way to get from this fact to the final factoring is to rewrite the middle term as the sum of two terms:
9x^2 + 9x + x + 1
Now, you can factor by pairs:
(9x^2 +9x) +(x +1)
= 9x(x +1) + 1·(x +1)
= (9x +1)(x +1)
