Select the correct answer.

A mistake was made in the steps shown to simplify the expression. Which step includes the mistake?

[tex]\[ \frac{1+3^2}{5}+|-10| \div 2 \][/tex]

Step 1: [tex]\[=\frac{1+3^2}{5}+10 \div 2\][/tex]

Step 2: [tex]\[=\frac{1+9}{5}+10 \div 2\][/tex]

Step 3: [tex]\[=\frac{10}{5}+10 \div 2\][/tex]

Step 4: [tex]\[=2+10 \div 2\][/tex]

Step 5: [tex]\[=12 \div 2\][/tex]

Step 6: [tex]\[=6\][/tex]

A. Step 5

B. Step 3

C. Step 4

D. Step 1



Answer :

To identify the mistake, let's carefully go through each step of the given expression:

[tex]\[ \frac{1 + 3^2}{5} + |-10| \div 2 \][/tex]

We begin by evaluating each step:

Step 1:
[tex]\[ \frac{1 + 3^2}{5} + 10 \div 2 \][/tex]
In this step:
- [tex]\(3^2\)[/tex] is evaluated as [tex]\(9\)[/tex].
- The absolute value of [tex]\(-10\)[/tex] is taken as [tex]\(10\)[/tex].

Therefore, the expression simplifies to:
[tex]\[ \frac{1 + 9}{5} + 10 \div 2 \][/tex]
Step 1 is correct.

Step 2:
[tex]\[ \frac{1 + 9}{5} + 10 \div 2 \][/tex]
Here, [tex]\(1 + 9\)[/tex] is evaluated as [tex]\(10\)[/tex]. Thus, the expression becomes:
[tex]\[ \frac{10}{5} + 10 \div 2 \][/tex]
Step 2 is also correct.

Step 3:
[tex]\[ \frac{10}{5} + 10 \div 2 \][/tex]
Now, [tex]\( \frac{10}{5} \)[/tex] is evaluated as [tex]\(2\)[/tex]. This simplifies to:
[tex]\[ 2 + 10 \div 2 \][/tex]
Step 3 is correct.

Step 4:
[tex]\[ 2 + 10 \div 2 \][/tex]
Here, [tex]\(10 \div 2\)[/tex] is evaluated as [tex]\(5\)[/tex]. The expression becomes:
[tex]\[ 2 + 5 \][/tex]
Step 4 is correct.

Step 5:
[tex]\[ 2 + 5 \][/tex]
The sum [tex]\(2 + 5\)[/tex] should equal [tex]\(7\)[/tex]. However, in the steps provided, it is incorrectly shown as:
[tex]\[ 12 \div 2 \][/tex]

This is incorrect because [tex]\(2 + 5\)[/tex] should be [tex]\(7\)[/tex], not [tex]\(12 \div 2\)[/tex].

Step 6:
This final step results from the incorrect value in Step 5:
[tex]\[ 6 \][/tex]

Therefore, the mistake is in:

Step 5: where [tex]\(2 + 5\)[/tex] should correctly equal [tex]\(7\)[/tex], not [tex]\(12 \div 2\)[/tex].

The correct answer is:
A. Step 5