Respuesta :

x^2 + 7x + 12
Steps
First, break the expression into groups
= (x^2 + 3x) + (4x + 12) 
Factor out x from x^2 + 3x: x(x + 3)
Factor out 4 from 4x + 12: 4(x + 3)
= x (x + 3) + 4(x + 3)
Then, factor out the common term (x + 3)
= (x + 3) (x + 4)