Answer:
(x+1)(x+3)
Explanation:
Let's factor x^2+4x+3
x^2+4x+3
The middle number is 4 and the last number is 3.
Factoring means we want something like
(x+_)(x+_)
Which numbers go in the blanks?
We need two numbers that...
Add together to get 4
Multiply together to get 3
Can you think of the two numbers?
Try 1 and 3:
1+3 = 4
1*3 = 3
Fill in the blanks in
(x+_)(x+_)
with 1 and 3 to get...
(x+1)(x+3)