Let the x-axis represent the temperature in Celcsius and y-axis represent the temperature in Fahrenheint.

Look at picture below.

The y-intercept is 32 because for 0 celius we have 32 fahrenheint.

The other point is (100,212).

Find the slope,

The y-intercept is 32 as explained before.Code:212-32 9 -------- = -- 100-0 5

Thus, the equation of the line is, i.e. conversion formula from celius to fahrenheit is.

y=(9/5)x+32