3.2 Solving Inequalities Using
+/Objective: SWBAT solve inequalities
using addition and subtraction.
Mini Quiz 20
1.
Graph x < 4
0
2.
Is 2 a solution to 4n – 3 < 5?
3.
When you graph, how do you tell if the dot is
open or close?
4.
When you graph, how do you tell which side to
shade?
Overview


Solving inequalities using addition and/or
subtraction
Solving and checking solutions
Quick Review
1. When you graph, how do you tell if the dot is
open or close?
close when it’s < or >
open when it’s ≤ or ≥
2. When you graph, how do you tell which side to
shade?
when x is smaller (< or ≤), shade to left
when x is bigger (> or ≥), shade to the right
Addition and Subtraction of Inequalities
Solve and graph each inequalities
Checking your solution:
1. x – 3 < 5
1. Check Computation 2.
+3 +3
x–3=5
8–3=5
x<8
5 = 5
0
Check Inequality
x–3<5
7–3<5
4 < 5
8
Addition and Subtraction of Inequalities
Solve and graph each inequalities ( solutions)
x<2
1. x + 3 < 5
m>2
2. m – 6 > -4
x ≥ -4
3. 1 ≤ x + 5
n≤5
4. n – 7 ≤ -2
0
Application
5. The maximum safe load of a chairlift is 680 lb.
A cyclist rides the chairlift with his bicycle.
The cyclist weights 124 lb, and the bicycle
weighs 32 lb. Which inequality best describes
how much additional weight w the chairlift
could safely carry?
a) 124  w  680  32
b) 32 w  680  124
c) 124  32  w  680
d) 124  32  w  680
Addition and Subtraction of Inequalities
Solve and graph each inequalities ( solutions)
y < -3.2
6. -4.1 > y – 0.9
m ≤ -3.5
7. m + 2.3 ≤ -1.2
3
8. 4  k 
4
k ≤ 19/4
0
Wrap Up

Solve inequalities by


+/-
Check solutions


 computation
 inequality
HW: P. 132 #1 – 37 EOO,
#43 – 55 EOO, 65 – 69 odd
Write DLUQ for the notes.