436) (720-a) * 6 - 200 = 340

Решение:

1. \( (720 - a) \cdot 6 - 200 = 340 \)
2. \( (720 - a) \cdot 6 = 340 + 200 \)
3. \( (720 - a) \cdot 6 = 540 \)
4. \( 720 - a = \frac{540}{6} \)
5. \( 720 - a = 90 \)
6. \( a = 720 - 90 \)
7. \( a = 630 \)

Ответ: a = 630.