Math

posted by .

The rule for multplying and dividing both sides of an inequality do not meantion zero. Explain why??

  • Math -

    In general, we do not multiply or divide each side of an equality by zero, as it could give erroneous results. So the same applies to inequalities.

    For example:
    A=B
    Multiply by A:
    A*A = A*B
    Subtract B²:
    A²-B² = AB - B²
    Factor each side:
    (A+B)(A-B) = B(A-B)
    Cancel out (A-B)
    A+B = B

    How does the fallacy work: we divided each side by (A-B) which is zero!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Pre-Algebra

    inequality 0.75x>3 Multiply both sides of the inequality by 4/3 if you want to know what x is. from where did you get 4/3 to multiply to find x. How do you know that?
  2. Math[Please Help]

    Solve the inequality x > 6x - 10 and write a description of the graph. Show all work Subtracting x from both sides does not change the inequality sign direction. 0 > 5x - 10 Add 10 to both sides 5x < 10 Divide both sides by …
  3. Math2(Please help)

    Directions:Solve and explain the inequality using words.Tell which wa shading goes. Problem: x+3=>2x+1 and -4x<-8 -4x<-8 The first inequality can be rewritten x <= 2 In words, x is less than or equal to 2. You can get that …
  4. maths

    6y=9-3x rearrange for x= Change 6y = 9 - 3x to: 3x = -6y + 9, then solve for x by dividing both sides by 3 to get: x = -2y + 3 when you divided both sides by 3. there is a rule where you cant divide the answer if theirs an addition …
  5. math

    f/2+>10......sole this inequality Frankly, it makes no sense If it is f/2 >=10 multipy both sides by 2 i meant f/2+5>10 subtract five from both sides, then multiply both sides by 2.
  6. math

    Why does the inequality sign change when both sides are multiplied or divided by a negative number?
  7. Pre-Algebra

    The rules for multipying and dividing both sides of an inequality do not mention zero. Explain why ?
  8. algebra

    Why does the inequality sign change when both sides are multiplied or divided by a negative number?
  9. Algebra

    Devin attempted to solve the inequality -2x+6>10 following the steps below: •subtract 6 from both sides of the inequality. •divide both sides of the inequality by -2. He finds that x>-2. Clearly explain why this is not a …
  10. Algebra, Please Help!

    Devin attempted to solve the inequality -2x+6>10 following the steps below: •subtract 6 from both sides of the inequality. •divide both sides of the inequality by -2. He finds that x>-2. Clearly explain why this is not a …

More Similar Questions