Transcript ANSWER a.) The see-saw depicts x + 3

The Wolves basketball team is
pictured below. Can you determine
the height of each player?
ANSWER
Player's Heights:
– King is 76.5 inches tall.
– Boomer is 79 inches tall.
– Julie is 74.5 inches tall.
– Carmello is 77 inches tall.
– Timmy is 72 inches tall.
– Larry is 75.25 inches tall.
a.) What inequality is depicted by this
see-saw?
b.) Solve the inequality for x?
ANSWER
a.) The see-saw
depicts x + 3 < 7.
b.) x + 3 < 7
x<4
Solving linear inequalities is
pretty much the same as
solving linear equations...
with one very important
exception.
Look at this true statement:
Suppose we multiply both
sides by -1.
5>3
(-1)(5) ? (3)(-1)
-5 ? -3
What is the relationship between
these two numbers ?
ANS: -5 is less than -3 because it is
further to the left on the number
line.
-5
< -3
So we just learned the one
exception. That is:
When you multiply an
inequality by a
negative number, it
changes the direction
of the inequality.
This is also true if you
divide by a negative.
EXAMPLE:
-5x < 10
-5x < 10
-5
-5
x > -2
Divide both sides by negative 5
Dividing both sides by a negative
number reverses the inequality
sign.
Let’s Practice
•
1.
2.
3.
4.
Solve and Graph
-12 < 2r
r/3 > 2
x + 3 < -4
-4w > 12
-10
-5
0
5
10
Writing Inequalities
• Write an algebraic inequality
1. The recipe calls for not less than 16 ounces
of butter.
x ≥ 16
2. Mr. Valdez says he cannot contribute more
than $500.
x ≤ 500
3. The team will have to score no fewer than
20 points to win. x ≥ 20
4. The sleeping bag is useful for camping when
temperatures are at least -5F. x ≥ -5