Worked-out Problems
Worked-out Problems
Worked-out Problems
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Chapter 3 continued<br />
34. Your friend’s method:<br />
18 2x 36<br />
18 2x 2x 36 2x<br />
18 36 2x<br />
18 36 36 2x 36<br />
54 2x<br />
5 4<br />
2 x<br />
<br />
2 2<br />
27 x<br />
Your method:<br />
18 2x 36<br />
18 2x 18 36 18<br />
2x 54<br />
2<br />
<br />
x<br />
2<br />
54<br />
<br />
2<br />
x 27<br />
Sample answer: Both methods produce the same answer.<br />
Your method involved fewer steps by leaving the variable<br />
on the left side of the equation.<br />
35. a. Let m the number of months.<br />
b.<br />
Amount<br />
already<br />
saved<br />
Amount saved ($)<br />
800<br />
600<br />
400<br />
200<br />
<br />
278 50m<br />
Amount<br />
saved per<br />
month<br />
p<br />
Saving for Class Trip<br />
y<br />
0<br />
0 2 4 6 8 10 12m<br />
Number of months<br />
Number<br />
of<br />
months<br />
Number of Amount of<br />
months from now money saved<br />
0 $278<br />
1 $328<br />
2 $378<br />
3 $428<br />
4 $478<br />
Sample answer: The points lie along a straight line.<br />
Continue plotting points until you obtain a y-value of<br />
850. The corresponding x-value will give the number<br />
of months it will take to save enough money for the<br />
trip.<br />
––CONTINUED––<br />
35. ––CONTINUED––<br />
c. Let m the number of months.<br />
Amount Amount Number<br />
Total<br />
already saved per p of<br />
amount<br />
saved month months<br />
850 278 50m<br />
850 278 278 50m 278<br />
572 50m<br />
5 72<br />
5 0m<br />
<br />
50<br />
50<br />
11.44 m<br />
It will take ab<strong>out</strong> 12 months to save for the trip.<br />
d. Sample Answer:<br />
Part (a) method: An advantage is that the table<br />
shows the exact amount saved for every month. A<br />
disadvantage is that a table may need to become very<br />
large in order to find a solution.<br />
Part (b) method: An advantage is that the scatter<br />
plot shows the change from month to month. A<br />
disadvantage is that you may need to plot a large<br />
number of points in order to find a solution.<br />
Part (c) method: An advantage is that an equation will<br />
give an exact solution. A disadvantage is that it does<br />
not show the amount saved for each month.<br />
36. To solve x 2<br />
2, first multiply each side by 4.<br />
4<br />
4 x 2<br />
<br />
4 4(2)<br />
x 2 8<br />
Then subtract 2 from each side.<br />
x 2 2 8 2<br />
x 6<br />
Check: x 2<br />
2<br />
4<br />
6 2<br />
<br />
4<br />
2<br />
8 4 2<br />
2 2 ✓<br />
3.1 Mixed Review (p. 124)<br />
37. 11(6z 14) 11(6z) 11(14) 66z 154<br />
38. 9(2x 12) 9(2x) (9)(12)<br />
18x (108)<br />
18x 108<br />
39. 12(3 5y) 12(3) 12(5y) 36 60y 60y 36<br />
40. 8(4 7w) 8(4) 8(7w) 32 56w 56w 32<br />
Copyright © McDougal Littell/Houghton Mifflin Company<br />
All rights reserved.<br />
Chapter 3<br />
Pre-Algebra 73<br />
<strong>Worked</strong>-Out Solution Key
Change language