3x - 2 = 13

I need some hellp

You are on a cycling trip around europe with friends. you check the weather forecast for the first week. these are the temperatures for the week. sun mon tues wed thurs fri sat 16°c 20°c 24°c 28°c 28°c 23°c 15°c what is the mean temperature forecast for the week?

What is the radical expression that is equivalent to the expression 27 1 over 5?

Math i have no idea how to do a and b