To solve the inequality \( \frac{x-1}{7-5x} > 0 \), we need to determine where the expression is positive. This occurs when both the numerator and denominator are either both positive or both negative.
Step 1: Find where the numerator \( x - 1 > 0 \)
\[ x - 1 > 0 \implies x > 1 \]
Step 2: Find where the denominator \( 7 - 5x > 0 \)
\[ 7 - 5x > 0 \implies 7 > 5x \implies x < \frac{7}{5} \]
Step 3: Determine intervals
Now we have two conditions:
- \( x > 1 \)
- \( x < \frac{7}{5} \)
Combining these conditions, we find:
\[ 1 < x < \frac{7}{5} \]
Step 4: Sign analysis of critical points
Next, we need to consider the critical points:
- The numerator changes sign at \( x = 1 \)
- The denominator changes sign at \( x = \frac{7}{5} \)
We can summarize the sign chart:
- For \( x < 1 \): \( x - 1 < 0 \) and \( 7 - 5x > 0 \) → Overall negative.
- For \( 1 < x < \frac{7}{5} \): \( x - 1 > 0 \) and \( 7 - 5x > 0 \) → Overall positive.
- For \( x > \frac{7}{5} \): \( x - 1 > 0 \) and \( 7 - 5x < 0 \) → Overall negative.
Final Solution: The solution to the inequality \( \frac{x-1}{7-5x} > 0 \) is:
\[ x \in (1, \frac{7}{5}) \]
So, the final answer is:
\[ \boxed{(1, \frac{7}{5})} \]