Ответ:

1) х⁹х² = х⁹⁺² = х¹¹

2) аа⁷ = а¹⁺⁷ = а⁸

3) b³b³ = b³⁺³ = b⁶

4) 7¹¹ × 7³ = 7¹¹⁺³ = 7¹⁴

5) m⁴m⁵m¹¹ = m⁴⁺⁵⁺¹¹ = m²⁰

6) c¹⁹cc³ = c¹⁹⁺¹⁺³ = c²³

7) (a + b)(a + b)⁷ = (a + b)¹⁺⁷ = (a + b)⁸

8) n⁹n⁴nn³ = n⁹⁺⁴⁺¹⁺³ = n¹⁷