Help please it’s due at a certain time

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

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

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !