Michael solved this inequality as shown:



Step 1: $-6(x+3)+10<-2$

Step 2: $-6 x-18+10<-2$

Step 3: $-6 x-8<-2$

Step 4: $-6 x<6$

Step 5: $x>-1$



What property justifies the work shown between step 3 and step 4?


Atransitive property
Bdivision property of inequality
Cdistribution property
Daddition property of inequality

Verified Answer :

  • The inequality at step 3 is \(-6x - 8 < -2\).
  • To isolate the term \(-6x\), we add \(8\) to both sides of the inequality: \(-6x - 8 + 8 < -2 + 8\).
  • This results in \(-6x < 6\), which is the inequality at step 4.
  • Adding the same value to both sides of an inequality is justified by the addition property of inequality.
  • The correct answer is \(\boxed{\text{addition property of inequality}}\).

Explanation

  1. Analyzing the Transformation from Step 3 to Step 4

The problem asks to identify the property used to move from step 3 to step 4 in the solving process of the inequality \(-6(x+3)+10 < -2\).

In step 3, we have the inequality:
\[-6x - 8 < -2\]

In step 4, we have the inequality:
\[-6x < 6\]

To reach step 4 from step 3, we observe the change on both sides of the inequality. The term \(-8\) on the left-hand side of step 3 is eliminated to get \(-6x\) in step 4. This is achieved by adding \(8\) to both sides of the inequality:
\[(-6x - 8) + 8 < (-2) + 8\]
\[-6x + 0 < 6\]
\[-6x < 6\]

The property that allows adding the same value to both sides of an inequality without changing the solution set is the addition property of inequality.

  1. Conclusion

The transition from step 3 to step 4 is completed by adding 8 to both sides. The addition property of inequality states that if \(a < b\), then \(a + c < b + c\) for any real number \(c\). By applying this property with \(c = 8\), the transformation is justified. Therefore, the property that justifies the work shown between step 3 and step 4 is the addition property of inequality.

Examples

In real-world budgeting, if you have a debt of \(\$8\) and a current balance of \(\$-2\), and you receive a credit of \(\$8\), your new balance becomes \(\$6\). This mirrors the mathematical process of adding the same quantity to both sides of an inequality to isolate a variable term, helping you track financial adjustments efficiently and correctly. Maintaining balance in equations, just like in your bank account, ensures your calculations remain accurate and fair.