
Step-by-step explanation
Step 1
as we can see in the graph, the y axis ( dependent variable ) is for the temperature and the x-axis is for the time, so we need a function where the temperature(t) depends on the time( m)

Step 2
find the slope of the line:
when you have 2 points of the line, you can find the slope by using:

then , let
P1(0,0)
P2(8,50)
now, replace.

Step 3
finally, get the equation of the line:
use

now, replace.


so, the answer is

I hope this helps you