3 xþ 22 x¼ 44 22 xþ 22 x
25 x¼ 44
251 x
25
¼
44
25
x¼ 1 :76 hours
Find the distance usingD¼RT.
D¼RT
D¼ 3 ð 1 : 76 Þ
¼ 5 :28 miles
EVALUATION: The time he rode the bus is 21.76¼0.24 hours. The
distance isD¼RT.
D¼RT
D¼ 22 ð 0 : 24 Þ
¼ 5 :28 miles
EXAMPLE:A merchant mixes some coffee costing $4 a pound with some
coffee costing $3 a pound. How much of each must be used in order to make
20 pounds of mixture costing $3.75 a pound?
SOLUTION:
GOAL: You are being asked to find how much of each coffee should be used.
STRATEGY: Letx¼the amount of $4 coffee used
andy¼the amount of $3 coffee used
216 LESSON 18 Using Two Equations