At Westonci.ca, we make it easy for you to get the answers you need from a community of knowledgeable individuals. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

Find the student's error in solving the following inequality:

[tex]\[
\begin{array}{l}
31 \ \textless \ -5x + 6 \\
25 \ \textless \ -5x \\
-5 \ \textless \ x
\end{array}
\][/tex]

A. The student should have added 6 to both sides instead of subtracting it.
B. The student divided [tex]\(\frac{25}{-5}\)[/tex] incorrectly.
C. The student should have switched the direction of the inequality sign to get [tex]\(-5 \ \textgreater \ x\)[/tex] for a final answer.


Sagot :

Certainly! Let's go through the solution step-by-step:

1. Initial Inequality:
[tex]\[ 31 < -5x + 6 \][/tex]

2. Isolate the term with [tex]\( x \)[/tex]:
To isolate the term with [tex]\( x \)[/tex], we need to remove the constant term on the right-hand side. We do this by subtracting 6 from both sides:
[tex]\[ 31 - 6 < -5x + 6 - 6 \][/tex]
Simplifying this, we get:
[tex]\[ 25 < -5x \][/tex]

3. Correcting the Mistake:
The student correctly isolated the term with [tex]\( x \)[/tex] up to this point. However, the mistake occurs in the next step.

4. Dividing by -5:
When we divide or multiply both sides of an inequality by a negative number, we must reverse the direction of the inequality sign. Therefore, we divide both sides by -5 and switch the inequality sign:
[tex]\[ \frac{25}{-5} > x \][/tex]
Simplifying this gives:
[tex]\[ -5 > x \][/tex]

5. Rewriting the Final Step:
The inequality [tex]\( -5 > x \)[/tex] can also be written as:
[tex]\[ x < -5 \][/tex]

### Summary of Errors:
- The student did not switch the direction of the inequality sign when dividing by a negative number. The correct division resulted in [tex]\( -5 > x \)[/tex], and should have been reported as [tex]\( x < -5 \)[/tex].
- The initial steps were correct until the division by -5, where the direction of the inequality was not properly switched.

### Correction:
- Correct final inequality: [tex]\( x < -5 \)[/tex]

Final Correct Inequality:
[tex]\[ x < -5 \][/tex]

Answer:

C. The student should have switched the direction of the inequality sign to get-5 > x for a final answer.

Step-by-step explanation:

31 < -5x+6

Step 1: Subtract 6 from each side.

31-6 < -5x+6-6

25 < -5x

Step 2 : Divide each side by -5, remembering to flip the inequality.

25/-5 > -5x/-5

-5 > x