Answer:
( x + 4 ) ( 3x + 1 )
Step-by-step explanation:
→ Identify the product, sum & factors
Product = 4
Sum = 13
Factors = 4 & 1
3x² + 12x + x + 4
→ Factorise 3x² + 12x and x + 4
3x² + 12x ⇔ 3x ( x + 4 )
x + 4 ⇔ 1 ( x + 4 )
→ Take out the ( x + 4 ) as a factor and ( 3x + 1 )
( x + 4 ) ( 3x + 1 )
