Answer:
[tex]r^{-42}[/tex]
Step-by-step explanation:
(r⁻⁷)⁶ = r⁽⁻⁷⁾ˣ⁶
= (r)⁻⁴²
[tex] {r}^{ - 42} [/tex]
hope this helps you..!
[tex] ({r}^{ - 7}) ^{6} \\ = {r}^{ (- 7) \times 6} \\ = {r}^{ - 42} [/tex]