Answer:
see explanation
Step-by-step explanation:
Given
a = ![\left[\begin{array}{ccc}3\\2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%5C%5C2%5C%5C%5Cend%7Barray%7D%5Cright%5D)
To obtain -3a multiply each of the elements of a by -3
3a = ![\left[\begin{array}{ccc}-3(3)\\-3(2)\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-3%283%29%5C%5C-3%282%29%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}-9\\-6\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-9%5C%5C-6%5C%5C%5Cend%7Barray%7D%5Cright%5D)
To obtain 1.5a multiply each element by 1.5
1.5a = ![\left[\begin{array}{ccc}1.5(3)\\1.5(2)\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1.5%283%29%5C%5C1.5%282%29%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}4.5\\3\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4.5%5C%5C3%5C%5C%5Cend%7Barray%7D%5Cright%5D)
<span>N(t) = 16t ; Distance north of spot at time t for the liner.
W(t) = 14(t-1); Distance west of spot at time t for the tanker.
d(t) = sqrt(N(t)^2 + W(t)^2) ; Distance between both ships at time t.
Let's create a function to express the distance north of the spot that the luxury liner is at time t. We will use the value t as representing "the number of hours since 2 p.m." Since the liner was there at exactly 2 p.m. and is traveling 16 kph, the function is
N(t) = 16t
Now let's create the same function for how far west the tanker is from the spot. Since the tanker was there at 3 p.m. (t = 1 by the definition above), the function is slightly more complicated, and is
W(t) = 14(t-1)
The distance between the 2 ships is easy. Just use the pythagorean theorem. So
d(t) = sqrt(N(t)^2 + W(t)^2)
If you want the function for d() to be expanded, just substitute the other functions, so
d(t) = sqrt((16t)^2 + (14(t-1))^2)
d(t) = sqrt(256t^2 + (14t-14)^2)
d(t) = sqrt(256t^2 + (196t^2 - 392t + 196) )
d(t) = sqrt(452t^2 - 392t + 196)</span>
Answer:
19.2
Step-by-step explanation:
You get the mean of a set of numbers by adding them and dividing the sum by how many numbers there are. In this case, you don't know what the individual 8 numbers are, but you can find out what they add up to.
Mean = (sum) / 8
17 = (sum) / 8
17 x 8 = sum
136 = sum
Now take out the numbers 9, 11, 20, which reduces the sum by 40. There are 5 numbers left and they add up to 136 - 40 = 96.
The new mean is 96 / 5 = 19.2
Answer:
x = number of bicycles = 35
y = number of cars = 55
Step-by-step explanation:
Let
x = number of bicycles
y = number of cars
x + y = 80 (1)
2x + 4y = 270 (2)
From (1)
x = 80 - y
Substitute x = 80 - y into (2)
2x + 4y = 270 (2)
2(80 - y) + 4y = 270
160 - 2y + 4y = 270
- 2y + 4y = 270 - 160
2y = 110
y = 110/2
y = 55
Substitute y = 55 into (1)
x + y = 80 (1)
x + 55 = 80
x = 80 - 55
x = 35
x = number of bicycles = 35
y = number of cars = 55
Answer:
Step-by-step explanation:
