Solve the proportion using cross multiplication.

[tex]\[
\begin{array}{c}
\frac{3x - 3}{4} = \frac{2x + 1}{3} \\
x = \, ?
\end{array}
\][/tex]



Answer :

To solve the proportion [tex]\(\frac{3x - 3}{4} = \frac{2x + 1}{3}\)[/tex] using cross multiplication, follow these steps:

1. Set up the cross multiplication:

Multiply the numerator of the left fraction by the denominator of the right fraction and the numerator of the right fraction by the denominator of the left fraction:
[tex]\[ 3 \cdot (3x - 3) = 4 \cdot (2x + 1) \][/tex]

2. Distribute the constants:

Expand both sides of the equation:
[tex]\[ 3 \cdot (3x - 3) = 3 \cdot 3x - 3 \cdot 3 = 9x - 9 \][/tex]
[tex]\[ 4 \cdot (2x + 1) = 4 \cdot 2x + 4 \cdot 1 = 8x + 4 \][/tex]

So, the equation becomes:
[tex]\[ 9x - 9 = 8x + 4 \][/tex]

3. Isolate the variable:

First, let's move all the [tex]\(x\)[/tex] terms to one side of the equation and the constants to the other side. Subtract [tex]\(8x\)[/tex] from both sides:
[tex]\[ 9x - 8x - 9 = 4 \][/tex]
Simplifying this gives:
[tex]\[ x - 9 = 4 \][/tex]

4. Solve for [tex]\(x\)[/tex]:

Add 9 to both sides of the equation:
[tex]\[ x - 9 + 9 = 4 + 9 \][/tex]
Simplifying this gives:
[tex]\[ x = 13 \][/tex]

Thus, the solution to the equation [tex]\(\frac{3x - 3}{4} = \frac{2x + 1}{3}\)[/tex] is [tex]\(\boxed{13}\)[/tex].