1­3 OLD open sentences 3AB.notebook
February 01, 2013
OBJECTIVE: Solve open sentences
open sentence a math sentence that contains @ least one variable
two types 1. equation (=)
>
→ is greater than
ex. 3x ­ 4 = 45
→ is greater than
or equal to
<
→is less than
2. inequality (>, <, ≤, ≥, ≠)
→is less than
or equal to
ex. 3x ­ 4 ≥ 45
→is NOT equal to
/
means not
** an open sentence is neither TRUE nor FALSE until the variable(s)
are replaced with values
OBJECTIVE: Solve open sentences
set a collection of objects or numbers {in braces}
ex.
{2, 4, 6, 8, 10}
replacement set set of possible solutions for an open sentence
ex.
2y ­ 19 = 61 {10, 20, 30, 40, 50, 60}
replacement set
solution set
NOTES & homework
set of elements from the replacement set that
make the open sentence true
1
1­3 OLD open sentences 3AB.notebook
February 01, 2013
OBJECTIVE: Solve open sentences
solving an open
sentence
solve an open sentence by
1. substituting or replacing the elements from the
replacement set into the open sentence one at a
time
2. evaluate to see if the value makes the open
sentence true
3. each value that makes the open sentence true
is placed in a solution set
OBJECTIVE: Solve open sentences
example:
solution set {
***
NOTES & homework
}
At most 1 Solution
2
1­3 OLD open sentences 3AB.notebook
February 01, 2013
OBJECTIVE: Solve open sentences
example:
solution set {
***
}
can have more than one solution
OBJECTIVE: Solve open sentences
example:
solution set
**
NOTES & homework
EMPTY SET (means ­ no solution)
3
1­3 OLD open sentences 3AB.notebook
February 01, 2013
OBJECTIVE: Solve open sentences
YOU try:
Examples
OBJECTIVE: Solve open sentences
NOTES & homework
4
1­3 OLD open sentences 3AB.notebook
February 01, 2013
HOMEWORK: Practice worksheet 1­3 #'s 1­10, 17­22
­ complete on separate paper
­ write original problem
­ show all scratch work as modeled in class
NOTES & homework
5