Https://us-static.z-dn.net/files/d18/ce7107c58c34f8e2cf6c1f3e05752043.jpeg
Assuming that an exponentiation sign is missing, all you need to know is that rational exponents work like this:
![a^{\frac{b}{c}}=\sqrt[c]{a^b}](https://tex.z-dn.net/?f=a%5E%7B%5Cfrac%7Bb%7D%7Bc%7D%7D%3D%5Csqrt%5Bc%5D%7Ba%5Eb%7D)
So, you have

And similarly,
![81^{\frac{7}{4}}=\sqrt[4]{25^7}=\sqrt[4]{(3^4)^7}=3^7](https://tex.z-dn.net/?f=81%5E%7B%5Cfrac%7B7%7D%7B4%7D%7D%3D%5Csqrt%5B4%5D%7B25%5E7%7D%3D%5Csqrt%5B4%5D%7B%283%5E4%29%5E7%7D%3D3%5E7)
6 miles.
3 miles per hour times 2 hours.
3 x 2 = 6.
Answer:
40 minutes
Step-by-step explanation:
The least common multiple of 8 minutes and 10 minutes is ...
LCM(8, 10) = 8·10/GCD(8, 10) = 80/2 = 40
The red and blue trains will arrive together again in 40 minutes.