Page 123 - Math Course 2 (Book 1)

Trinomials: ax + bx + c
2

Your Turn! MO. 4 - L2b

2
Factor ax + bx + c Solving Equations :
2
2
Factor 3x + 26x + 35. ax + bx + c
A. (3x + 7)(x + 5)
B. (3x + 1)(x + 35) Vocabulary A-Z
C. (3x + 5)(x + 7) Let us learn some vocabulary
D. (x + 1)(3x + 7)

Answer
Prime Polynomial

A polynomial that cannot be written as a product of
two polynomials with integral coef cients is called a
prime polynomial.

There are no factors with
Factors Sum of
of –4 Factors a sum of 5. Therefore,
2
2
Factor 10x – 23x + 12. 1, –4 –3 2x + 5x – 2 cannot be
factored using integers.
–1, 4 3
2
A. (2x + 3)(5x + 4) Thus, 2x + 5x – 2 is a
B. (2x – 3)(5x – 4) –2, 2 0 prime polynomial.
C. (2x + 6)(5x – 2)
2
D. (2x – 6)(5x – 2) Factor 2x + 5x – 2
Answer
Let’s Begin

Determine Whether a Polynomial
is Prime

Example
2
Factor 2x + 14x + 20.
2
A. (2x + 4)(x + 5) Factor 3x + 7x – 5.
B. (x + 2)(2x + 10)
2
C. 2(x + 7x + 10) In this trinomial, a = 3, b = 7, and c = –5. Since b is
D. 2(x + 2)(x + 5) positive, m + n is positive. Since c is negative, mn is
negative, so either m or n is negative, but not both.
Therefore, make a list of all the factors of 3(–5) or
Answer –15, where one factor in each pair is negative. Look
for the pair of factors with a sum of 7.

Factors of Sum of
–15 Factors

–1, 15 14
1, 15 –14
–3, 5 2

3, –5 –2
115