SECTION 2.4 An Introduction to Applications of Linear Equations^115
NOW TRY Step 3 Write an equation.
EXERCISE 9
Find the measure of an angle
whose supplement is 46°
less than three times its
complement.
Be sure to use
parentheses here.Step 4 Solve. Distributive property
Combine like terms.
Add 2x.
Combine like terms.
Subtract 180.x= 10
180 + x- 180 = 190 - 180
180 + x= 190
180 - x+ 2 x= 190 - 2 x+ 2 x
180 - x= 190 - 2 x
180 - x= 10 + 180 - 2 x
Step 5 State the answer.The measure of the angle is 10°.
Step 6 Check.The complement of 10° is 80° and the supplement of 10° is 170°.
170° is equal to 10° more than twice 80° (that is, is true).
Therefore, the answer is correct. NOW TRY
170 = 10 + 21802
2.4 EXERCISES
1.Concept Check A problem requires finding the number of cars on a dealer’s lot. Which
would notbe a reasonable answer? Justify your response.A. 0 B. 45 C. 1 D.2.Concept Check A problem requires finding the number of hours a lightbulb is on dur-
ing a day. Which would notbe a reasonable answer? Justify your response.
A. 0 B.4.5 C. 13 D. 25
3.Concept Check A problem requires finding the distance traveled in miles. Which would
notbe a reasonable answer? Justify your response.A. B.1.8 C. D. 504.Concept Check A problem requires finding the time in minutes. Which would notbe a
reasonable answer? Justify your response.
A. 0 B.10.5 C. D. 90Solve each problem. See Example 1.
5.The product of 8, and a number increased by 6, is 104. What is the number?
6.The product of 5, and 3 more than twice a number, is 85. What is the number?
7.If 2 is added to five times a number, the result is equal to 5 more than four times the num-
ber. Find the number.
8.If four times a number is added to 8, the result is three times the number, added to 5. Find
the number.
9.If 2 is subtracted from a number and this difference is tripled, the result is 6 more than
the number. Find the number.
10.If 3 is added to a number and this sum is doubled, the result is 2 more than the number.
Find the number.- 5
10
1
2
- 10
6
1
2
Complete solution available
on the Video Resources on DVD
Supplement is 10 more than twice its complement.180 - x = 10 + 2 # 190 - x 2
NOW TRY ANSWER
9.22°