3,6/х-1=7,8/6,5

To solve the equation \( \frac{3.6}{x - 1} = \frac{7.8}{6.5} \), we can start by simplifying the right side.

1. Calculate \( \frac{7.8}{6.5} \): \[ \frac{7.8}{6.5} = \frac{78}{65} = \frac{78 \div 13}{65 \div 13} = \frac{6}{5} = 1.2 \]

2. Now, rewrite the equation: \[ \frac{3.6}{x - 1} = 1.2 \]

3. Cross-multiply to eliminate the fraction: \[ 3.6 = 1.2(x - 1) \]

4. Distribute \(1.2\) on the right side: \[ 3.6 = 1.2x - 1.2 \]

5. Add \(1.2\) to both sides to isolate the term with \(x\): \[ 3.6 + 1.2 = 1.2x \] \[ 4.8 = 1.2x \]

6. Now, divide both sides by \(1.2\): \[ x = \frac{4.8}{1.2} \] \[ x = 4 \]

So, the solution is \( x = 4 \).