Answer:
1) The equation of the temperature in function of the time is
T(t) = 12 - 2t, with t in hours
The temperature is -4F after 8 hours, so, at P.M.
2) 6.75 = 7.50r
Her rate of deductions is 10% a day.
Step-by-step explanation:
1) This problem can be modeled by a first order equation
T(t) = T(0) + rt
In which T(0) is the temperature at instant zero and r is the rate of growth(r>0) or decline(r<0).
Since at 12 noon, the temperature outside is 12F, T(0) = 12. The temperature drops at the steady rate of 2F an hour, so r = -2.
The equation of the temperature in function of the time is
T(t) = 12 - 2t, with t in hours
The temperature is -4F when
-4 = 12 - 2t
2t = 16
t = 8h
The temperature is -4F after 8 hours, so, at P.M.
2) This problem can be modeled by the following first order equation
P = rP(0).
Where P is her pay, r is the rate of the initial money that Zelly takes home and P(0) is her initial pay.
In hour problem, we have that P = $6.75 and P(0) = $7.50.
So
6.75 = 7.50r
r = 0.9 means that Zelly keeps 90% of her pay. It means that her rate of deductions is 10% a day.
Answer
Find out the Area of a triangle .
To proof
Formula
Area of Triangle
Now vertices are D(3, 3) , E(3, −1) , and F(−2, −5) .
Solving the above
= -10 units²
(Neglected the negative sign as area cannot be negative.)
= 10 units ²
Area of a triangle is 10 units ²
Hence proved