Study Guide and Intervention (continued) - MathnMind
Study Guide and Intervention (continued) - MathnMind
Study Guide and Intervention (continued) - MathnMind
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12-3<br />
Dimensional Analysis Multiplying fractions that involve units of measure can be<br />
simplified by dividing units of measure. This is similar to simplifying rational expressions<br />
by dividing out common factors.<br />
Example<br />
The tank of a car holds 15 gallons of gasoline. You want to travel<br />
1200 miles on a vacation. If the car averages 24 miles per gallon, how many tanks<br />
of gasoline can you expect to use for this trip?<br />
1200 miles 1 gallon 1 tank<br />
1 trip 24 miles 15 gallons<br />
Use dimensional analysis.<br />
1200 miles 1 gallon 1 tank<br />
1 trip 24 miles 15 gallons<br />
Divide similar units.<br />
1200 tank<br />
360 trip<br />
Simplify.<br />
1<br />
3 tanks/trip<br />
3<br />
Simplify.<br />
1<br />
You can expect to use 3 tanks of gasoline for the trip.<br />
3<br />
Exercises<br />
NAME ______________________________________________ DATE ____________ PERIOD _____<br />
<strong>Study</strong> <strong>Guide</strong> <strong>and</strong> <strong>Intervention</strong> (<strong>continued</strong>)<br />
Multiplying Rational Expressions<br />
Find each product.<br />
1 mile 32 blocks<br />
1. <br />
8 blocks 3 hours<br />
8 centimeters 1 meter 1 kilometer<br />
2. <br />
1 pin 100 centimeters 1000 meters<br />
50 miles 5280 feet 1 hour 1 minute<br />
3. <br />
1 hour 1 mile 60 minutes 60 seconds<br />
2000 revolutions 60 minutes 24 hours 7 days<br />
4. <br />
1 minute 1 hour 1 day 1 week<br />
5. CARPETING Sarina’s living room is 15 feet by 18 feet. What will it cost to carpet the<br />
living room if carpet costs $24 per square yard?<br />
6. CHARITY WALK Suppose you participate in a walk for charity by asking for pledges.<br />
You walk at a constant rate of 2 miles per hour <strong>and</strong> have pledges totaling $15 per mile.<br />
How much do you earn for the charity if you walk for 16 hours?<br />
7. PAINTING Suppose you estimate that the exterior of your house will need 15 gallons of<br />
paint. You use a special paint sprayer that holds one quart of paint. How many times do<br />
you need to fill the sprayer to paint the house?<br />
8. CALORIES The number of calories used to play volleyball depends on your weight <strong>and</strong><br />
how long you play. Playing volleyball expends 2.2 Calories per hour per pound of weight.<br />
If you weigh 130 pounds, how many Calories do you use in 1.5 hours?<br />
9. GARDENING The rectangular lawns in a tract housing development each measure<br />
100 feet by 200 feet. A gardener can cut 1000 square yards of grass per hour. How many<br />
2<br />
of these lawns can he cut in 6 hours?<br />
3<br />
© Glencoe/McGraw-Hill 718 Glencoe Algebra 1
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