Answer: The factors are 3 and 1
Explanation:
We have to find two factors that will be multiplied to give 3
and at the same time add to give 4x , these factors are 3x and x , which will replace the number in the middle, then the expression becomes
+ 3x + x + 3
x(x+3) + 1 (x + 3)
(x+3)(x+1)