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1.Is each number a solution of x > –1?
a. 3 b. –5
2.Is 2 a solution of 3x – 4 < 2?
3.Graph x > 4.
yes no
no
Math on the Mind
Solving One-Step InequalitiesAddition and Subtraction
Unit 6
Lesson 2
hrsbstaff.ednet.ns.ca/matkins/.../PowerPoints/6.1%20Inequalities.ppt
Let’s Review the Inequality Symbols:
• http://www.brainpop.com/math/dataanalysis/inequalities/preview.weml
Solving an Inequality
Solving an inequality is a lot like solving an equation. Isolate the variable on one side using inverse operations.
Solve:
53 x+3 +3
x < 8
hrsbstaff.ednet.ns.ca/matkins/.../PowerPoints/6.1%20Inequalities.ppt
Solving an Inequality
106 x
4x-6 -6
hrsbstaff.ednet.ns.ca/matkins/.../PowerPoints/6.1%20Inequalities.ppt
p – 4 < 1
p < 5
Solve p – 4 < 1. Graph the solution.
+ 4 + 4 Add 4 to each side.
8 d – 2
10 d Simplify.
Solve 8 d – 2. Graph your solution.
+ 2 + 2 Add 2 to each side.
k > –5–3 –3
k +3 > –2
Solve and graph.
–5 0
www.ezwebsite.org/Photos/files1778/4CH2L5.ppt
r 21
+ 9 + 9r – 9 12
21 2415
Solve and graph.
www.ezwebsite.org/Photos/files1778/4CH2L5.ppt
u 8
+ 5 + 5u – 5 3
8 1050
Solve and graph.
www.ezwebsite.org/Photos/files1778/4CH2L5.ppt
c –4
–6 –6c + 6 2
0 4–7 –4
Solve and graph.
www.ezwebsite.org/Photos/files1778/4CH2L5.ppt
In order to receive a B in your literature class, you must earn more than 350 points of reading credits. Last week you earned 120 points. This week you earned 90 points. How many more points must you earn to receive a B?
Define: Let = the number of points needed.p
Write: 120 + 90 + 350p >
210 + p > 350 Combine like terms.
– 210 – 210 Subtract
You must earn 141 more points.
p > 140 Simplify.
Which statement can be modeled by x + 3 12?
A. Sam has 3 bottles of water. Together, Sam and Dave have at most 12 bottles of water.
B. Jennie sold 3 cookbooks. To earn a prize, Jennie must sell at least 12 cookbooks.
C. Peter has 2 baseball hats. Peter and his brothers have fewer than 12 baseball hats.
D. Kathy swam 3 laps in the pool this week. She must swim more than 12 laps.
• Your brother has $2,000 saved for a vacation. His airplane ticket is $637. Write and solve an inequality to find out how much he can spend for everything else.
• Your local bank offers free checking for accounts with a balance of at least $500. Suppose you have a balance of $516.46 and you write a check for $31.96. How much do you need to deposit to avoid being charged a service fee?
