Page 522 - Algebra 1

Example
3
Practice
Distributed and Integrated
(Ex 2)
f.
(Ex 3)
12 3 6
Athletics A student runs a quarter-mile in 180 seconds. She improves her time by 5 seconds each week. To find the number of weeks w needed for her time to be at most 150 seconds, solve the inequality 180 - 5t ≤ 150.
Application: Loans
A student borrows $55 from his parents. They agree to subtract $3 from the loan for each hour he works in the yard. To find the number of hours, x, he needs to work before he owes less than $30, solve the inequality 55 - 3x < 30.
Caution
Remember to change the direction of the inequality symbol when multiplying or dividing both sides by a negative number.
SOLUTION
55 - 3x < 30 -3x < -25
_ x > 25
x > 8_1 3
Subtract 55 from both sides. Divide both sides by -3.
Simplify.
3
Hint
Explain the meaning of the solution after solving a real-world problem.
He must work more than 8_1 hours. 3
Solve each inequality and graph the solutions. a. 4x+29≤25
(Ex 1)
b. -36 - 7k < 6 (Ex 1)
c. -18 + (-3) < -4f + 11 (Ex 2)
d. -5(10 - 5p) > (-10)2 (Ex2)_1 _2_5
Lesson Practice
e. y+ ≥
Use the stem-and-leaf plot to find the following statistical measures. 1. Find the median.
Average Milk Production
(62) 3
2. Find the mode. (62)
3. Factor the expression 6x2 - 10x - 4 completely. (75)
4. Solve 9 > 0.3r. (70)
*5. Solve 5 + 4x > 37, and then graph the solution. (77)
4 5 6
Stem
Leaves
5, 7
1, 6, 7, 7, 7, 8, 8, 9, 9 0, 2, 3, 6
1, 1
Key: 6 1 means 61 pounds
Lesson 77 507