Why do astronauts wear shiny suits for space walks?

Explanation:

Astronauts must wear spacesuits whenever they leave a spacecraft and are exposed to the environment of space. In space, there is no air to breath and no air pressure... Spacesuits are specially designed to protect astronauts from the cold, radiation and low pressure in space. They also provide air to breathe.

the expression 15n + 2(3p) represents the amount isaiah spent buying gasoline and snacks, where n represents the price of each gallon of gasoline and p represents the cost of each snack that he bought. which statement is true about the amount isaiah spent?