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Ch. 1-5 Absolute Value Equations and Inequalities. Ex. 1: Solve | 15 – 3x | = 6. | 15 – 3x | = 6. 15 – 3x = 6. 15 – 3x = -6. -15 -15. -15 -15. -3x = -9. -3x = -21. x = 7. x = 3. Solve Check understanding 1 p. 33. Ex. 2: 4 – 2|x + 9| = -5. 4 – 2|x + 9| = -5.
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Ex. 1: Solve | 15 – 3x | = 6 | 15 – 3x | = 6 15 – 3x = 6 15 – 3x = -6 -15 -15 -15 -15 -3x = -9 -3x = -21 x = 7 x = 3
Ex. 2: 4 – 2|x + 9| = -5 4 – 2|x + 9| = -5 -4 -4 -2|x + 9| = -9
Ex. 3 cont. -9 -9 -9 -9 x = -13.5 x = -4.5
Ex. 3: Solve |3x – 4| = -4x - 1 3x – 4 = -4x – 1 3x – 4 = 4x + 1 -3x -3x +4x +4x 7x – 4 = -1 -4 = x + 1 -1 -1 +4 +4 x = -5 7x = 3
When there is a variable outside of the absolute value, you must check your answers. x = -5 | 3(-5) – 4 | = -4(-5) -1 | -15 – 4 | = 20 - 1 | -19 | = 19 19 = 19 Solution Not a solution
Ex. 4: Solve | 2x – 5 | > 3. Graph the solution. 2x – 5 < -3 2x – 5 > 3 +5 +5 +5 +5 2x < 2 2x > 8 x < 1 x > 4
Ex. 5: Solve -2| x + 1 | + 5 > -3 -2| x + 1| + 5 > -3 -5 -5 -2| x + 1| > -8 | x + 1| < 4
Ex. 5 cont. x + 1 > -4 x + 1 < 4 -1 -1 -1 -1 x < 3 x > -5
Ex. 6: The area A in square inches of a square photo is required to satisfy 8.5 < A < 8.9. Write this requirement as an absolute value inequality. Find the tolerance. Find the average of the maximum and minimum values -.2 < A – 8.7 < .2 Write the inequality Rewrite as an absolute value inequality | A – 8.7 | < .2
Homework p. 36 – 37 # 1 – 53 eoo