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41 votes
41 votes
-3|2x+1|<4 how is this solved

User Cbliard
by
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1 Answer

12 votes
12 votes

Answer:

True for all x

Explanation:

  • Multiply by -1. This reverses the inequality.


-3\left|2x+1\right| < 4\\\left(-3\left|2x+1\right|\right)\left(-1\right) > 4\left(-1\right)

  • Remember: Negative * Positive = Negative
  • Remember: Negative * Negative = Positive


3\left|2x+1\right| > -4:\:Solve\\4* -1 = -4\\\left(-3|2x+1|\right)\left(-1\right)\\\left(-3* -1\right)\\\left(-3|2x+1|)

  • Divide by 3


=(3\left|2x+1\right|)/(3) > (-4)/(3)

___________


(3\left|2x+1\right|)/(3)\\(3)/(3)\\= (1)/(1)

___________


= (1)/(1) > (-4)/(3)

___________


-(4)/(3)\\= -(4)/(3)

  • Because absolute values are greater than or equal to 0, the problem will be classified as "True" for any value of x no matter what.

Hope this helps.

User Edovino
by
2.5k points