B is directly proportional to a.
b is 10 when a is 8.
Work out b when a is 9.

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

The measure of an angle is 117°. what is the measure of a supplementary angle?

Write the equation in general quadratic form: plz !