Page 152 - Algebra 1

Lesson Practice
a. Justify Which step would you use first to evaluate 9y + 6 for y = 2? (Ex 1) Explain.
b. Justify Which step would you use first to solve 9y + 6 = 24? Explain. (Ex 1)
Solve each equation. Then check the solution.
c.
(Ex 2)
e.
(Ex 4)
f.
(Ex 5)
8w-4=28 d. -10=-2x+12 (Ex 3)
Solve _1 m + _3 = _7 . Then check the solution to see if it is reasonable. 8 4 12
Energy Conservation The Green family conserves energy by using energy-efficient bulbs. They pay $125 for energy-efficient bulbs. If the family saves $7 per month on their electricity bill, and the power company gives them a rebate of $25, in about how many months will they have paid for the bulbs?
Practice
Distributed and Integrated
1. Evaluate (x - y) - (x - y) for x = 3.5 and y = 2.5. (9)
2. Write Explain how to graph the point (-2, 4). (20)
*3. Multiple Choice What is the value of x in the equation 3x + 5 = 32? _1
(23)
A 24 B 9 C 81 D 123
4. Error Analysis Two students solve -12x = -72. Which student is correct? Explain
(21) the error.
*5. Altitude A plane increases altitude by 350 meters every minute. If the plane (17) started at an altitude of 750 meters above sea level, what is the plane’s altitude
after 6 minutes?
6. Verify Is x = 9 the solution for 3x - 8 = 22? Explain. If false, provide a correct
(23) solution and check.
7. Justify Find a counterexample to the following statement: A rational number
Student A
-12x = -72 -12x =-72
__ 12 12
x = -6
Student B
-12x = -72 -12x = -72
__ -12 -12
x=6
(1) that is not an integer, such as _3 , multiplied by any integer will produce a rational
5 number that is not an integer.
Lesson 23 137