To simplify the given rational expression, we need to factor both the numerator and the denominator and then cancel out any common factors.
Step 1: Factor the Numerator
The numerator of the given rational expression is \(x^2 - 7x + 10\). We factor this quadratic expression:
\[
x^2 - 7x + 10 = (x - 5)(x - 2)
\]
Step 2: Factor the Denominator
The denominator of the given rational expression is \(x^2 + 4x - 12\). We factor this quadratic expression:
\[
x^2 + 4x - 12 = (x - 2)(x + 6)
\]
Step 3: Simplify the Rational Expression
We now have the factored form of the rational expression:
\[
\frac{x^2 - 7x + 10}{x^2 + 4x - 12} = \frac{(x - 5)(x - 2)}{(x - 2)(x + 6)}
\]
We can cancel the common factor \((x - 2)\) from the numerator and the denominator:
\[
\frac{(x - 5)(x - 2)}{(x - 2)(x + 6)} = \frac{x - 5}{x + 6}
\]
Final Answer
The simplified form of the given rational expression is:
\[
\boxed{\frac{x - 5}{x + 6}}
\]