Answer:
(x+1) (x+3)
Step-by-step explanation:
Use the sum-product pattern
x²+4x+3
4x = 3x + x
= x²+3x+x+3
common factor from two pairs
x²+3x+x+3
= x²( x+3 )+x+3
= x(x+3) +x+3
Rewrite in factored form
= (x+1) (x+3)
So the answer must be (x+1)(x+3)
