x² + 3x: common factor is x
1x + 3: common factor is 1
From here I do not understand how you get to the answer which I do know is (x + 1) • (x + 3).
None of the explanations out there give detail to this step. I don’t understand how adding those two groups up (while pulling out common factors) will give you (x + 1) • (x + 3)!
I would hugely appreciate any help on this! Thank you :)