Answer:
Mr.Lin's present age is 30 years now. His son is 8 years old now.
Step-by-step explanation:
Let L = Mr.Lin's present age,
S = his son's present age.
First equation is
L + S = 38. (1)
The second equation is
L + 3 = 3*(S+3) (2) ("In three years' time, Mr.Lin will be three times as old as his son.")
From (1), express S = 38-L and substitute it into (2). You will get
L + 3 = 3*((38-L)+3), or
L + 3 = 114 - 3L + 9,
4L = 114 + 9 - 3,
4L = 120,
L = 30.
To determine the number of cars that will be sold by the year 2020, we will use the equation,
N = (N1)(1 - r)^(t)
where N1 is the starting number of cars, r is the rate of the decrease, and t is the number of years from 2012. Substituting the konwn values,
N = (500)(1 - 0.028)^(8)
N = 398.38
The closest integer to the calculated value is 398. Thus, the answer is 398 cars.
C. 4
14 + 13 - (23)
27 - 23
4
The variable b represents the area of the base of the prism or pyramid. Hope that helps!
Answer:
B) 12d-4
Step-by-step explanation:
3d+4+9d-8
3d+9d+4-8
12d+4-8
12d-4
