Answer:
There is no correct answer given.
Answer should be t=-2h+21.
Step-by-step explanation:
General format of a linear equation can be given as,
y= mx + c
Where,
y ⇒ dependent variable ( in this case temperature t)
m⇒ Gradient ( the rate at which the temperature drops)
x⇒ independent variable ( hours )
c⇒ intercept ( this is the starting temperature)
Now we can substitute the given values to the above format to arrive at the equation,
t=-2h+21
There is no correct answer given.