5. If [tex]a = 4.3[/tex], then which demonstration shows that [tex]34.4 \div a = 8[/tex] is true?

A.
[tex]\[
\begin{array}{l}
34.4 \div a = 8 \\
34.4 + 4.3 = 42.7 \\
42.7 = 42.7
\end{array}
\][/tex]

B.
[tex]\[
\begin{array}{l}
34.4 \div a = 8 \\
4.3 \div 34.4 = \frac{1}{8} \\
\frac{1}{8} = \frac{1}{8}
\end{array}
\][/tex]

C.
[tex]\[
\begin{array}{l}
34.4 \div a = 8 \\
34.4 - 4.3 = 30.1 \\
30.1 = 30.1
\end{array}
\][/tex]

D.
[tex]\[
\begin{array}{l}
34.4 \div a = 8 \\
34.4 \div 4.3 = 8 \\
8 = 8
\end{array}
\][/tex]



Answer :

To determine which demonstration correctly shows that [tex]\(34.4 \div a = 8\)[/tex] is true when [tex]\(a = 4.3\)[/tex], let's go through each option step-by-step:

### Option 1
[tex]\[ \begin{array}{l} 34.4 \div a = 8 \\ 34.4 + (4.3) = 42.7 \\ 42.7 = 42.7 \end{array} \][/tex]
This option is incorrect. The second line, [tex]\(34.4 + 4.3 = 42.7\)[/tex], does not demonstrate division. It adds [tex]\(34.4\)[/tex] and [tex]\(4.3\)[/tex], which is not relevant to verifying [tex]\(34.4 \div 4.3\)[/tex].

### Option 2
[tex]\[ \begin{array}{l} 34.4 \div a = 8 \\ (4.3) \div 34.4 = \frac{1}{8} \\ \frac{1}{8} = \frac{1}{8} \end{array} \][/tex]
While this option results in a true statement ([tex]\(\frac{1}{8} = \frac{1}{8}\)[/tex]), it does not directly verify that [tex]\(34.4 \div 4.3\)[/tex] equals 8. It shows the reciprocal relationship without directly addressing the original division.

### Option 3
[tex]\[ \begin{array}{l} 34.4 \div a = 8 \\ 34.4 - (4.3) = 30.1 \\ 30.1 = 30.1 \end{array} \][/tex]
This option is incorrect. The subtraction [tex]\(34.4 - 4.3 = 30.1\)[/tex] does not help verify the division statement [tex]\(34.4 \div 4.3 = 8\)[/tex].

### Option 4
[tex]\[ \begin{array}{l} 34.4 \div a = 8 \\ 34.4 \div (4.3) = 8 \\ 8 = 8 \end{array} \][/tex]
This option is correct. It directly performs the division:
[tex]\[ 34.4 \div 4.3 = 8 \][/tex]
and then confirms that 8 equals 8.

Thus, the correct demonstration is option 4:
[tex]\[ \begin{array}{l} 34.4 \div a = 8 \\ 34.4 \div(4.3) = 8 \\ 8 = 8 \end{array} \][/tex]