To solve the problem, we need to express the rate at which each person works and then combine those rates.
- Person A can complete the job in 6 hours, so their rate is \( \frac{1}{6} \) of the job per hour.
- Person B can complete the job in 7 hours, so their rate is \( \frac{1}{7} \) of the job per hour.
When working together, their combined rate is the sum of their individual rates.
Let \( t \) be the time (in hours) they work together. The equation representing their combined work would be:
\[ \frac{1}{6}t + \frac{1}{7}t = 1 \]
Therefore, the correct choice among the options provided is:
A. \( \frac{1}{6}t + \frac{1}{7}t = 1 \)