Choose the correct factored form for each expression. ^ ^ ee Problem 5.
- k2 + 5 kn - 84n2 A. {k - 7 n){k - 12 n) B. {Jc - l n ) [ k + 12n)
33. p2 - 8pq - 33q2 A. [p + 3q)(p - lie?) B. ( p - 3 q ){p + U q )
34. x2 - 16 xy + 48y 2 A. (x - 4y)(x + 12y) B. (x - 4y)(x - 12y)
Factor each expression.
- r 2 + 19rs + 90s2 36. g 2 - 12gh + 35h2 37. m2 - 3mn - 28n2
- x2 + 3xy - 18y2 39. w2 - 14wz + 40z2 40. p2 + llp q + 24q2
,1 ^ Apply ^ 41. Writing Suppose you can factor x 2 + bx + c as (x + p){x + q).
a. Explain w h at you know ab o u t p a n d q w h e n c > 0.
b. Explain w hat you know ab o u t p a n d q w h e n c < 0.
- Error Analysis D escribe an d correct th e error m ad e in factoring th e trinom ial.
@ 4 3. T h in k A b o u t a P lan The area of a parallelogram is given by th e trinom ial
x2 - 14x + 24. The base of the parallelogram is x - 2. W hat is a n expression for the
height of th e parallelogram?
- W hat is th e form ula for the area of a parallelogram?
- How can you tell w h e th e r th e binom ial th at rep resen ts th e height has a positive
or negative constant term?
- Recreation A rectangular skateboard p ark has an area of x2 + 15x + 54. W hat are
the possible dim ensions of th e park? Use factoring.
Write the standard form of each polynomial modeled below. Then factor
each expression.
6 x2 4x
9x
4x2 10 x
2 x
@ 47. Reasoning Let x2 - 13x - 30 = (x + p){x + q).
a. W hat do you know ab o u t the signs of p a n d ql
b. Suppose |p | > \q\. W hich n u m b er, p or q, is a negative integer? Explain.
@ 48. Reasoning Let x 2 + 13x - 30 = (x + p)(x + q).
a. W hat do you know ab o u t the signs of p an d < 7?
b. Suppose | p | > | q |. W hich num ber, p o r q, is a negative integer? Explain.
516 Chapter 8 Po l y n o m i al s an d Fact o r i n g