Transcript Agenda 11/8 & 11/9

Agenda 11/8 & 11/9
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Warm UP
Go Over Homework
Absolute Value
Absolute Value Equations (1 & 2 step)
Quiz on Solving Equations
Homework
Warm UP
1) I=r t solve for t
2) 4x + 2y = 8
solve for y
3) mn + 7 = p solve for m
4) 12x + 8y + 2z = 20 solve for z
5) 8x - 4y = -60 solve for y
Go Over Homework
1) D (1st one) 2) C
4) R
5) Omit
7) N
8) O (1st one)
10) D (1st one) 11) Omit
3) A
6) E (2nd one)
9) O (2nd one)
12) D (2nd one)
Did you get 5 of them right? Grade = 100
4 right? Grade = 80 3 right? Grade = 60
2 right? Grade = 40 1 right? Grade = 20
Absolute Value
On the number line given to you:
Mark a dot on zero
Now move 5 places
Compare number lines
Where should you be?
Both +5 and -5 are correct, why?
Absolute Value
Absolute value is the numbers distance
away from zero on the number line.
The absolute value of #, denoted "| # |" (and
which is read as "the absolute value of #"),
is regarded as the distance of # from zero.
Note: The absolute value notation is bars, not
parentheses or brackets.
Absolute Value
Evaluate:
1) | –8 |
2) | 4.1 |
3) | 0 |
4) | 5 |
What do absolute values do to positive numbers?
What do absolute values do to zero?
What do absolute values do to negative numbers?
Absolute Value Equations
Use mental math to
solve the equation.
1) | x | = 3
Use mental math to
solve the equation.
2) | x | = -5
Ask yourself “what
numbers are 3 units
from zero?”
What numbers have a
distance of -5 from
zero?
Worksheet A; 1-3
Absolute Value Equations
To solve an absolute value equation, you can use
the fact that the expression inside the absolute
value can be either positive or negative.
EX 1: | x – 2 | = 5
Well x- 2 can equal 5 or -5, so we have 2
equations!
a) x – 2 = 5 or
b) x – 2 = - 5
+ 2 +2
+ 2 +2
x = 7 or
x = -3 ,
Check and see they are both solutions. WS A; 4-6
Absolute Value Equations
Let’s take it further:
EX 2: | 2x – 7| = 11
Well 2x – 7 can equal 11 OR -11
a) 2x – 7 = 11 OR b) 2x – 7 = -11
WS A; 7-9
Quiz on Solving Equations
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Clear off your desk.
Keep your paper covered.
When you are done, bring the quiz to me.
After you complete the quiz you may work
on your homework.
Homework
Worksheet B; 1-9 (green paper)