If the temperature of a liquid can be measured in kelvin units as x°K or in Fahrenheit units as y°F, the relation between the two systems of measurement of temperature is given by the linear equation.
(i) find the temperature of the liquid in Fahrenheit, if the temperature of the liquid is 313°K.
(ii) If the temperature is 158°F, then find the temperature in Kelvin.
(i) 
Put x = 313 in this equation, we get-
⇒ y = 72 + 32
⇒ y = 104°F
(ii)
Put y = 158 in the equation, we get-
790 = 9x – 2457 + 160 (multiplying whole equation by 5)
9x = 3087
x = 343K
5