Question 1043722
The intercept is at 72 degrees where t=0
The slope is -2 degrees/hour, because after 1 hour, it is 2 degrees less, after 2 hours, 4 degrees less, after 4 hours, 8 degrees less. 
y=-2x+72
{{{graph(300,300,0,8,-20,80,-2x+72)}}}
Tick marks are 10 degrees on the y-axis and 1 hour on the x-axis.