Transcript Do Now 12/8/06

Do Now 12/14/09
Take out HW from Friday.
– Text p. 359, #4-14 even 22-36 even
Copy HW in your planner.
– Text p. 366, #16-32 even, 36 & 40.
Complete the activity on page 362 in your
textbook. Read through the “Explore” steps #13. Then complete the “Draw Conclusions”
problems #1-8.
Homework
Text p. 359, #4-14 even 22-36 even
4) a ≥ 16
6) x ≤ -4
8) x > 4
10) x < 1
12) m ≥ -4¼
14) v > -15.8
22) 8 should have been subtracted from both sides of the inequality. x < -11.
24) 11 + m > -23; m > -34
26) c – 13 < -19; c < -6
28) x ≤ 3.3
30) x < 17.7
32) at least 33 goals
34) C
36) 2 axles: w ≤ 19,800, 3 axles: w ≤ 39,800, 4 axles: w ≤ 54,800,
5 axles: w ≤ 65,800. No, the total weight, 34,200 would exceed the
maximum weight allowed, 34,000 pounds.
Investigating Algebra Activity
“Inequalities with Negative Coefficients”
Complete the activity on page 362 in your
textbook. Read through the “Explore”
steps #1-3. Then complete the “Draw
Conclusions” problems #1-8.
Section 6.2
“Solve Inequalities Using Multiplication and
Division”
INEQUALITIES –
mathematical sentence formed by
placing a <, ≤, >, or ≥ between two
expressions.
11 - a ≤ 121
On a number line, the GRAPH OF AN
INEQUALITY in one variable is the set of
points that represent all solutions of the
inequality.
“Less than” and “greater
than” are represented
with an open circle.
Graph x < 3
-2
-1
“Less than or equal to”
and “greater than or equal
to” are represented with
closed circle.
-2
0
1
2
3
Graph x ≥ -1
-1
0
1
2
3
Solve
x
< 5 . Graph your solution.
4
x
< 5.
4
4 x <4 5
4
x < 20
Write original inequality.
Multiply each side by 4.
Simplify.
ANSWER
The solutions are all real numbers
less than 20. Check by substituting
a number less than 20 in the
original inequality.
Solve
8
m
≤–2
8
m
≤–2 8
8
m ≤ – 16
m
≤ -2 Graph your solution.
8
Write original inequality.
Multiply each side by 8.
Simplify.
The solutions are all real numbers less than are
equal to – 16. Check by substituting a number
less than – 16 in the original inequality.
Solve Inequalities When Multiplying and Dividing
by a NEGATIVE”
Multiplying and/or dividing each side
of an inequality by a NEGATIVE number
only produces an equivalent inequality
IF the inequality sign is REVERSED!!
Solve
m
– 7 < 1.6
m
– 7 – 7 > – 7 1.6
m > – 11.2
m
< 1.6
–7
Write original inequality.
Multiply each side by – 7.
Reverse inequality symbol.
Simplify.
ANSWER
The solutions are all real numbers greater than – 11.2.
Check by substituting a number greater than – 11.2 in the
original inequality.
Solve –3x > 24.
–3x > 24.
–3x
< 24
–3
–3
x<–8
Write original inequality.
Divide each side by –3. Reverse
inequality symbol.
Simplify.
Solve a real-world problem
A student pilot plans to spend 80 hours on flight training to
earn a private license. The student has saved $6000 for training.
Which inequality can you use to find the possible hourly rates r
that the student can afford to pay for training?
A 80r < 6000 B 80r <
– 6000 C 80r >
– 6000 D 80r > 6000
SOLUTION
The total cost of training can be at most the amount of money
that the student has saved. Write a verbal model for the
situation. Then write an inequality.
80
r
The correct answer is B. A
<
–
B
6000
C
D
Solve a real-world problem
What are the possible
hourly rates that the
student can afford to pay
for training?
80
r ≤ 6000
80r ≤ 6000
80
80
r ≤ 75
Write inequality.
Divide each side by 80.
Simplify.
The student can afford to pay at most $75 per hour
for training.
Algebra in “Real-Life!”
In your groups, complete the “real-life”
activity.
– Interdisciplinary Application “Bald Eagles”
Algebra in “Real-Life!”
In your groups, complete the two “real-life”
activities.
– Interdisciplinary Application “Bald Eagles”
1) y = 393x + 14,324
2) graph
3) approximately 18,254
4) habitat loss, less people counting
5) y = 512.5x + 13,698
6) graph
7) approximately 18,880
NJASK7 Prep
24
Homework
Text p. 366, #16-32 even, 36 & 40