#3 and #9 geometry !! Pls help

Yoku is putting on sunscreen. he uses 2\text{ ml}2 ml to cover 50\text{ cm}^250 cm 2 of his skin. he wants to know how many milliliters of sunscreen (c)(c) he needs to cover 325\text{ cm}^2325 cm 2 of his skin. how many milliliters of sunscreen does yoku need to cover 325 \text{ cm}^2325 cm 2 of his skin?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

When a valve is open 281 gallons of water go through it in one hour the number of gallons that would go through in 94 hours is