Answer:
(x + 1) * (x + 4)
Step-by-step explanation:
y = x² + 5x + 4
First, you multiply the first coefficient by the third coefficient: 4
Then you find all the factors of 4:
Of all these factors, you must find the pair that adds to 5 (the second coefficient)
Those factors are: 1 and 4
Then you put those into (x+_) and multiply them together:
( x + 1 ) * ( x + 4 )