1. Section 5.2
Factoring Trinomials
Of the Type x2 + bx +c
Phong Chau

2. x2 + 5x + 2x + 10 ( x + 2 )( x + 5) = = x2 + 7x + 10
The product of 2 binomials is a trinomial.
The constant term in the trinomial is the product of the constant terms in the binomials.
The coefficient of x in the trinomial is the sum of the constant terms in the binomials

3. x2 - 7x + 3x - 21 ( x + 3 )( x - 7) = = x2 - 4x - 21
The constant term in the trinomial is negative constant terms in the binomials are opposite in sign:
One must be positive +
The other is negative -

4. Factoring trinomials of the form x2 + bx + c:
The factored form must be product of 2 binomials ( x )( x )
To figure out the constants, look for 2 integers whose product is c and whose sum is b:
List all factor pairs of c.
Choose the factor pair whose sum is b

5. Examples
1) x2 + 7x + 10
2) x2 + 4x - 12
3) x2 - 6x - 16
4) 2a a a

6. Examples

7. Group exercise
1) x2 - 8x + 16
2) m2n + 4mn - 12n
3) 6x2y2 + 24xy y2