The time, T
(seconds), it takes for a pot of water to boil is proportional to the amount,
A
(litres), of water.
It takes 210 seconds to boil 2.5 litres of water.
Work out how long it takes (to the nearest second) to boil 2.9 litres.

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.