⚖️

Understanding and Solving Inequalities

May 15, 2025

Solving Inequalities

Problem Statement

  • Solve the inequality ( \frac{2}{3} > -4y - 8 \frac{1}{3} ).

Steps to Solve

Convert Mixed Numbers

  1. Convert Mixed Number to Improper Fraction
    • Convert ( 8 \frac{1}{3} ) to improper fraction:
      • ( 8 \frac{1}{3} = \frac{25}{3} )
    • Rewriting the inequality:
      • ( \frac{2}{3} > -4y - \frac{25}{3} )

Eliminate Fractions

  1. Multiply by 3 to Eliminate Fractions
    • Multiply both sides by 3:
      • ( 3 \times \frac{2}{3} > 3 \times (-4y - \frac{25}{3}) )
    • Simplify:
      • Left side: ( 2 )
      • Right side: ( -12y - 25 )
    • New inequality:
      • ( 2 > -12y - 25 )

Isolate the Variable

  1. Move Constant Terms

    • Add 25 to both sides:
      • ( 2 + 25 > -12y )
    • Simplified to:
      • ( 27 > -12y )
  2. Solve for y

    • Divide both sides by -12 (note the inequality swap):
      • ( \frac{27}{-12} < y )
    • Simplify fraction:
      • ( y > -\frac{9}{4} )

Solution Interpretation

  • Final Solution: ( y > -\frac{9}{4} )

Additional Representations

  • Mixed Number: ( y > -2 \frac{1}{4} )

Graphical Representation

  • Number Line:
    • Draw a number line with points ( 0, -1, -2, -3 )
    • Plot ( -2 \frac{1}{4} ) with an open circle
    • Shade to the right of ( -2 \frac{1}{4} ) to represent all values greater than this.

Key Concepts

  • Converting mixed numbers to improper fractions for easier manipulation.
  • Eliminating fractions by multiplying through by the least common denominator.
  • Sign change in inequality when multiplying or dividing by a negative number.