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Course: General Mathematics — Second Secondary
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Curriculum

General Mathematics — Second Secondary

Text lesson

Solving Equations and Inequalities

General Mathematics — Second Secondary

Solving Equations and Inequalities

Absolute value inequalities

Absolute value inequalities

  • For a positive number a:
Comparison aspectMain ideaKeywords
|x| < a
  • is equivalent to −a < x < a
  • so x lies inside an interval around zero
equivalentliesinsideinterval
|x| ≤ ais equivalent to −a ≤ x ≤ aequivalent
|x| > a
  • is equivalent to x > a or x < −a
  • so x lies outside the interval
equivalentliesoutsideinterval
|x| ≥ ais equivalent to x ≥ a or x ≤ −aequivalent
•
  • Note that the word “or” gives a union of two intervals
  • while “and” gives their intersection
Notewordgivesunion
•Write the solution with the correct notation for each caseWritesolutioncorrectnotation
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