Convert 0.347 kilometers to miles

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

What is the base of 1/9 to the power of 2