To solve the quadratic equation \( x^2 - 13x + 42 = 0 \) by grouping, we need to split the middle term, \(-13x\), into two terms that add up to \(-13\) and multiply to \(42\) (the constant term).
We are looking for two numbers \(a\) and \(b\) such that:
- \( a + b = -13 \)
- \( a \cdot b = 42 \)
After considering factor pairs of \(42\), we find:
- \( (1, 42) \)
- \( (2, 21) \)
- \( (3, 14) \)
- \( (6, 7) \)
Out of these pairs, we need a pair that adds up to \(-13\). The appropriate pair is \(-6\) and \(-7\) since:
- \(-6 + (-7) = -13\)
- \(-6 \cdot -7 = 42\)
Thus, the two numbers are \(-6\) and \(-7\). To complete the step of splitting the middle term, we write:
\[ x^2 - 6x - 7x + 42 = 0 \]
So the answer is: \(-7, -6\)