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Zorluk: KolayLinear Inequalities and Absolute Value

If 3x2+4>11-3|x - 2| + 4 > -11, which of the following inequalities represents all possible real values of xx?

  1. 3<x<7-3 < x < 7Cevap
  2. B
    x<3 or x>7x < -3 \text{ or } x > 7
  3. C
    x<7x < 7
  4. D
    7<x<3-7 < x < 3
  5. E
    5<x<5-5 < x < 5

Cevap

3<x<7-3 < x < 7
Subtracting 44 from both sides gives 3x2>15-3|x - 2| > -15. Dividing by 3-3 and reversing the inequality sign results in x2<5|x - 2| < 5. Converting to the compound inequality 5<x2<5-5 < x - 2 < 5 and adding 22 to each part yields the correct interval 3<x<7-3 < x < 7.

Adım Adım Çözüm

1
Subtract 4 from both sides of the inequality
3x2>15-3|x - 2| > -15
Isolate the absolute value term on the left side.
2
Divide both sides by 3-3 and reverse the inequality sign
x2<5|x - 2| < 5
Dividing an inequality by a negative number reverses the direction of the inequality symbol.
3
Express the absolute value inequality as a compound inequality
5<x2<5-5 < x - 2 < 5
An inequality of the form u<c|u| < c (where c>0c > 0) is equivalent to c<u<c-c < u < c.
4
Add 2 to all three parts of the compound inequality
3<x<7-3 < x < 7
Isolate xx to find the complete range of solution values.

Anahtar Kavram

Linear Inequalities and Absolute Value
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