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Do Now. Solve a compound inequality with “or”, Graph. 2x + 3 < 9 or 3x – 6 > 12 Solve a compound inequality with “and”, Graph. -6 < 3n + 9 < 21. Simplify:. Evaluate:. If x = -6. If a = 2. Objective: To solve absolute value equations. Using Absolute Value in Real Life.
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Do Now Solve a compound inequality with “or”, Graph. 2x + 3 < 9 or 3x – 6 > 12 Solve a compound inequality with “and”, Graph. -6 < 3n + 9 < 21
Evaluate: If x = -6 If a = 2
Using Absolute Value in Real Life The graph shows the position of a diver relative to sea level. Use absolute value to find the diver’s distance from the surface.
When do we use absolute value Determine the difference in altitude between: Death Valley (86 meters below sea level) -86 Mt Everest (8,840 meters above sea level).+ 8840 -86-8840= -8826
Absolute Value Absolute Value- of a number is the distance between the number and zero on a number line ** No such thing as a negative distance **
Solving absolute value equations • If |x| = 5, then what values of x would make the equation true?
If |x| = 5, then is |5| = 5 true? • If |x| = 5, then is |-5|=5 true?
x = -5 x = 5
Practice • = 3 = - 4 =2
Solving absolute value equations ? • |x - 2| = 5 What goes in the box to make the equation true? 5 or -5
Solving absolute value equations ? • |x - 2| = 5 Now lets remove the box and set what’s behind it equal to 5 and -5
Solving absolute value equations • |x - 2| = 5 Now lets remove the box and set what’s behind it equal to 5 and -5
Solving Absolute Value Equations x – 2 = 5 x – 2 = -5 x = 7 x = -3 Or
Ex: Solve 6x-3 = 15 6x-3 = 15 or 6x-3 = -15 6x = 18 or 6x = -12 x = 3 or x = -2 * Plug in answers to check your solutions!
On an index card make up an absolute value equation for your partner to solve. Trade cards.
Solve Two steps Absolute Value Equations • Steps • 1) Isolate the absolute value first • 2) Write it as two equations • 3)solve each equation • 4)test both solutions
Ex: Solve 2x + 7 -3 = 8 Get the abs. value part by itself first! 2x+7 = 11 Now split into 2 parts. 2x+7 = 11 or 2x+7 = -11 2x = 4 or 2x = -18 x = 2 or x = -9 Check the solutions.
6|5x + 2| = 312 • Isolate the absolute value expression by dividing by 6. 6|5x + 2| = 312 |5x + 2| = 52 • Set up two equations to solve. • 5x + 2 = 52 5x + 2 = -52 • 5x = 50 5x = -54 • x = 10 or x = -10.8 • Check:6|5x + 2| = 312 6|5x + 2| = 312 • 6|5(10)+2| = 312 6|5(-10.8)+ 2| = 312 • 6|52| = 312 6|-52| = 312 • 312 = 312 312 = 312
3|x + 2| -7 = 14 • Isolate the absolute value expression by adding 7 and dividing by 3. 3|x + 2| -7 = 14 3|x + 2| = 21 |x + 2| = 7 • Set up two equations to solve. • x + 2 = 7x + 2 = -7 • x = 5 or x = -9 • Check:3|x + 2| - 7 = 14 3|x + 2| -7 = 14 • 3|5 + 2| - 7 = 14 3|-9+ 2| -7 = 14 3|7| - 7 = 14 3|-7| -7 = 14 • 21 - 7 = 14 21 - 7 = 14 • 14 = 14 14 = 14
Exit Ticket • In your own words explain what is the difference between solving regular equations and absolute value equations?