Umm whats y2 when y is -9 and whats z2 when z is 0.7 im not that smart so ill be asking alot

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

Aculinary club earns $1360 from a dinner service. they sold 45 adult meals and 80 student meals. an adult meal costs twice as much as a student meal. what is the cost of an adult meal?

Tanyss's house has 25 windows. her brother has washed 22 of the windows. what percent of the windows has her brother washed?