Page 649 - Algebra 1

Example
5
Practice
Distributed and Integrated
Factor completely.
1. 3x3 -9x2 -30x
(Inv 9)
3. 32x3 -24x4 +4x5 (79)
2. 8x3y2 +4x2y-12xy3 (Inv 9)
4. mn3 -10mn2 +24mn (79)
634 Saxon Algebra 1
Application: Traveling
A pilot’s single-engine aircraft flies at 230 kph if there is no wind. The pilot
plans a round trip to a city that is 400 kilometers away. If there is a tailwind 400
of w kilometers per hour, the time for the outbound flight is _230 + w hours. The time for the return flight with a headwind of w kilometers per hour
400 _
is 230 - w hours. What is the total time for the round trip? SOLUTION
400 + 400 __
230 + w 230 - w
LCD = (230 + w)(230 - w)
Add to find the total time. Find the LCD.
Write equivalent fractions.
Expand the numerator and collect like terms.
400(230 - w) + 400(230 + w) ____
(230 + w)(230 - w) = 184,000
(230 + w)(230 - w) hours
__ (230 + w)(230 - w)
__ The round trip takes 184,000
hours.
5x - 45 x2 - 81 ___
b. 3x - 12
x + 4 x2 + 2x - 8
_2_ c.Add 3x +x-1.
(Ex 2) x2 - 25 4x - 20 _2_
d. Subtract 2x - 3x-4.
(Ex 3) 6x - 24
x2 - 16 e.Addx-1+ 2 .
(Ex 4)
f. Subtract (Ex 4)
2 2_2
__
x2 - 1
5
_ 5x +_
(230 + w)(230 - w)
Lesson Practice
Find the LCD for each expression.
(Ex 1) _ _ a. 5x - 44
1
- .
x -36 x +6x 4x
12 _
g. Trenton hiked x2 - 64 miles on Saturday and 7x - 56 miles on Sunday. (Ex 5) How many miles did he hike altogether?