Question

How do you evaluate `5^-7 times 5^9`?

Answer 1

`5^2`

Explanation:

Negative exponents: `a^-b=1/a^b`

Therefore, `5^-7=1/5^7`

`1/5^7*5^9=5^9/5^7`

Rule of exponents: `a^b/a^c=a^(b-c)`

Therefore, `5^(9-7)=5^2=25`