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Today:
Khan Academy, Mid-Progress, Mid-Term Tests, Other
Review: Equations, Integers & Rational Numbers
Continue: Absolute Value Expressions & EquationsClass Work
Monday, September 30, 2013
Khan Academy Notes:
Saturday & Sunday: 53 students logged on. Sunday: 1430 minutes = 23.83 hours Be sure to add me ([email protected]) as a coach or I cannot see your progress
Topics for October 6, 2013
1. Absolute Value Equations
2. Equivalent forms of Expressions 13. Constructing & Solving Equations in
the Real World
Mid Progress Reports Grades will only include:
Class Work: 20% Khan Academy: 20% Tests (2): 40%
Mid-Term Test: Two Part Test, 10 questions each Part I, Wednesday; Expressions,
Equations, Integers, Rational Numbers—See Today’s Class Work
Part II, Thursday; Absolute Value Expressions and Equations
Algebra vs. Pre-Algebra
Notebooks… Will be collected October 11th. All notebook issues need to be worked out before then
Open Notebook to warm up section
Warm Up:
1. (-|4 - 8|)2
Equations: 1-Step1. x + 4 = 11 Equations: 2-Step
1. 2x + 4 = 18 2. 3x - 5 = 10
3. 16 - 4|4 - 8| = 2
2. 5 - |7 - 10|
2. x - 5 = 83. 2x = 20 4. x/5 = 6
* The same rules to solving equations apply, there are just more steps to the solution.
1. 10y - (4y + 8) = -20
Multi-Step Equations
2. −8z −(2+3z) = 5(z + 3)
Solving Equations with Variables on Both Sides
When an equation has variables on both sides, three different results are possible.
Look at this equation: 2x + 2 = 4 + x The equation results in a solution of a single number.
In this case, x = 2
A 2nd Possibility
3x - 9 = 3x + 10
A linear equation has NO SOLUTION when the solved equation has no variable and the equation is false.
3x - 3x = no variable, -9 = 10
A 3rd Possibility
When an equation has variables on both sides, something else may occur. Solve the equation:
4(x – 5) = 4x - 204x -20 = 4x -20; Subtract 4x from the left side and -20 = -20This is called “identity”. It means ALL REAL NUMBERS make the sentence true.
A linear equation is an identity when the solved equation has NO VARIABLE and the solution is TRUE!
So… When solving equations with variables on both sides, 3 different things can happen.
1) solution is a single number ( x = 4)
2) solution is ALL REAL Numbers ( IDENTITY)
3) solution is NO SOLUTION (empty set)
Warm-Up (5); fr. Test
Version 1
3) 5(4d – 2) = 2d -1 A) 2 B) C) 4 D) 9 E) None4) 7x – 5 – x = -1 – 6x + 6 – 3x A) B) 1 C) 3 D) 1 E) 1
1) .3x + .3 = .6x + .7 - .5x A) .32 B) 15 C) 2 D) .4 E) None
8) - 6 = x - (2 + x) A) 28 B) -18 C) 30 D) -22 E) 32
Version 2
Version 39) The first stage of a rocket burns 28 seconds
longer than the second stage. If the total burning time for both stages is 182 seconds, how many seconds does the first stage burn for?
A) 124 B) 77 C) 98 D) 90 E) 105