What is 63.4721 to 1 decimal place

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *

Micheal is 4 times as old as brandon and is also 27 years older than brandon. how old is micheal