A student solves the equation [tex]\frac{x+3}{2} = \frac{3x+5}{5}[/tex] using the steps in the table.

\begin{tabular}{|c|c|}
\hline Original equation & [tex]\frac{x+3}{2} = \frac{3x+5}{5}[/tex] \\
\hline Cross multiplication & [tex]5(x+3) = 2(3x+5)[/tex] \\
\hline Distributive property & [tex]5x + 15 = 2(3x + 5)[/tex] \\
\hline Subtraction property of equality & [tex]5 = x[/tex] \\
\hline
\end{tabular}

Which method of solving for the variable could be used instead of cross multiplication?

A. Distributing [tex]x+3[/tex] and then [tex]3x+5[/tex] to both sides of the equation

B. Distributing [tex]x-3[/tex] and then [tex]3x-5[/tex] to both sides of the equation

C. Using the multiplication property of equality to multiply both sides of the equation by 10

D. Using the multiplication property of equality to multiply both sides of the equation by [tex]\frac{1}{10}[/tex]



Answer :

To solve the equation [tex]\(\frac{x+3}{2}=\frac{3 x+5}{5}\)[/tex], a different method instead of cross multiplication could be used. Let's explore the options:

- Distributing [tex]\(x+3\)[/tex] and then [tex]\(3 x+5\)[/tex] to both sides of the equation: This method isn't straightforward in this context as we cannot directly distribute expressions across a division.

- Distributing [tex]\(x-3\)[/tex] and then [tex]\(3 x-5\)[/tex] to both sides of the equation: Similar to the previous approach, distributing [tex]\(x-3\)[/tex] and [tex]\(3 x-5\)[/tex] across a division doesn't directly help in solving the equation.

- Using the multiplication property of equality to multiply both sides of the equation by 10: Multiplying both sides of the equation by 10 is an effective and straightforward method to eliminate the denominators. Here's how:

[tex]\[ \frac{x+3}{2} = \frac{3 x+5}{5} \][/tex]

Multiply both sides by 10:

[tex]\[ 10 \cdot \frac{x+3}{2} = 10 \cdot \frac{3 x+5}{5} \][/tex]

Simplify:

[tex]\[ 5(x+3) = 2(3x+5) \][/tex]

This then simplifies to:

[tex]\[ 5x + 15 = 6x + 10 \][/tex]

Using the subtraction property of equality, subtract [tex]\(5x\)[/tex] and 10 from both sides:

[tex]\[ 15 - 10 = 6x - 5x \][/tex]

Simplify and solve for [tex]\(x\)[/tex]:

[tex]\[ x = 5 \][/tex]

- Using the multiplication property of equality to multiply both sides of the equation by [tex]\(\frac{1}{10}\)[/tex]: Multiplying by [tex]\(\frac{1}{10}\)[/tex] would complicate the equation further rather than simplifying it as we aim to clear the fractions.

Thus, the most effective alternative method to cross multiplication is:
using the multiplication property of equality to multiply both sides of the equation by 10.