What is 17x13 divide by four

What is the point-slope equation of a line with slope -5 that contains the point (6,3)

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

Solve for n? [tex]z = \frac{3}{4} mn[/tex]