Factor the following trinomial: x2+ 4x +3

Step 1

identify a,b, and c in the trinomial ax2 + bx+c

a = 1b = 4c = 3

Step 2

write down all factor pairs of 3

Step 3

identify which factor pair from the previous step sums up to 4 (Note: since 4 is positive we only need to think about pairs that are either both positive or both negative. Remember a negative times a negative is a positive)

Step 4

Substitute that factor pair into two binomials

(x +3)(x+1)

Step 5

If you'd like, you can check your work by multiplying the two binomials and verify that you get the original trinomial

Exercises

x2+5x +6

x2 - 2x -3

x2 -5x +6

x2 -2x -15