a) You are told the function is quadratic, so you can write cost (c) in terms of speed (s) as
... c = k·s² + m·s + n
Filling in the given values gives three equations in k, m, and n.
Subtracting each equation from the one after gives
Subtracting the first of these equations from the second gives
Using the next previous equation, we can find m.
Then from the first equation
[tex]28=100\cdot 0.01+10\cdot (-1)+n\\\\n=37[tex]
There are a variety of other ways the equation can be found or the system of equations solved. Any way you do it, you should end with
... c = 0.01s² - s + 37
b) At 150 kph, the cost is predicted to be
... c = 0.01·150² -150 +37 = 112 . . . cents/km
c) The graph shows you need to maintain speed between 40 and 60 kph to keep cost at or below 13 cents/km.
d) The graph has a minimum at 12 cents per km. This model predicts it is not possible to spend only 10 cents per km.
Could be 154. 154 rounded to nearest ten= 150, rounded to nearest 100= 200
Answer:
there are 6 activities therefore 360/6 = 60 minutes on each activity
Step-by-step explanation:
Q1) 20 minutes past 8
Q2) Four O’clock
The answer to this rests on knowing that there are four properties of multiplication (which your teacher will likely expect you to know...):
These are:
1. commutative
2. associative
3. multiplicative identity
4. distributive
I won't define each of these -- they should be in your notes or textbook. Look them up.
In this case, we are multiplying three terms together -- on the left hand side the parentheses mean to multiply a and b first, then multiply that by 3. On the right hand side, we multiply b times 3 first, and then multiply the product by a.
This would be an example of the associative property of multiplication: when three or more factors are multiplied together, the product is the same regardless of how the factors are grouped.
Hope this helps!
Good luck
