How do you get rid of a power in an equation?

Why do interests rates on loans to be lower in a weak economy than in a strong one

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?

Julie multiplies 6.27 by 7 and claims the product is 438.9 .explain without multiplying how you know juliesanswer is not correct.find the correct answer