Question

Select the correct answer. A mistake was made in the steps shown to simplify the expression. Which step includes the mistake? 1 + 32 5 + -10 : 2 Step 1: = 1 + 32 5 + 10 : 2 1 Step 2: = + 10 = 2 10 Step 3: = 5 + 10 = 2 Step 4: = 2 + 10 = 2 Step 5: = 12 = 2 Step 6: = 6 OA. Step 4 OB. Step 3 OC. Step 5 D. Step 1

Answer 1

$\frac{1+3^2}{5}+\lbrack-10\rbrack\div2$

To simplify any expression you have to remember the following:

Multiplications and divisions come first, sum and subtractions come second.

This means that you have to solve the divisions first, and then you add the results:

Starting from left to rigth

First step is to simplify the fraction

$\begin{gathered} \frac{1+9}{5}+\lbrack-10\rbrack\div2 \\ \frac{10}{5}+\lbrack-10\rbrack\div2 \end{gathered}$

Step two is to solve the division: -10÷2

$\begin{gathered} \frac{10}{5}+(-10)\div2 \\ \frac{10}{5}-5 \end{gathered}$

Finally you have to subtract 5 from 10/5

$\frac{10}{5}-5=-3$

The error was made in step 4, where the sum was made before the division.