Page 15 - Math Course 3 (Book 1)

Multiplying and Dividing Linear Inequalities

Your Turn!

Write and Solve an Inequality Multiply by a Negative Number

1
SCHOOL Solve – x > 10
2
At Midpark High School, of the junior class 3
3
attended the dance. There were at least 200 juniors 10
at the dance. How many students are in the junior A. x > 3
class? 10
B. x > –
A. j ≤ 300 3
B. j ≥ 300 C. x < – 30
C. j ≥ 200
D. j ≤ 200 D. x > – 30

Answer Answer

MO. 1 - L2b

Solving Linear Inequalities:

Division

Key Concept Dividing by a Negative

Number
Dividing by a Positive
Number Words If each side of a true inequality is
divided by the same negative number,
Words If each side of a true inequality is the direction of the inequality symbol
divided by the same positive number, must be reversed so that the resulting
the resulting inequality is also true. inequality is also true.

Symbols If a and b are any numbers and c is a Symbols If a and b are any numbers and c is a
positive number, the following are true. negative number, the following are true.
a
b
b
a
if a > b, then > , and if a > b, then < , and
c c c c
b
a
b
a
if a < b, then < if a < b, then >
c c c c
This property also holds for inequalities involving This property also holds for inequalities involving
> and < > and <

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