The rate of change of stamp collection was $57.5 per year.
Rate is comparison of two related quantities.
Often the second quantity is time (per second, per hour, etc) but it can be anything.
Can be in the style "this per that" or as a single number calculated using division.
Example: Sam makes 3 pancakes every 6 minutes, that is a rate of:
• 3 pancakes per 6 minutes
• 0.5 pancakes per minute
• 30 pancakes per hour
• an hourly rate of 30
By formula the rate of change = Change in cost/ Time taken
=( $980 - $420)/ 8years
= $460/ 8 years
= $57.5 per year
Thus the rate of change of stamp collection was $57.5 per year.
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<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>
Better deal normlly means the rate that cost less
rate=cost/amount
9=cost and 3/4 bushel = amount for one store
3/4=0.75
9/0.75=12/1 aka $12/1bushel
9 =cost and 2/3 bushel =amount for another
2/3=about 0.66666
9/0.66666=13.5/1 aka $13.5/1 bushell
compare
12 dollars per bushe vs 13.5 dollar per bushel
12 is cheaper
therefor $9 For 3/4 bushel is better deal
Answer:
x = -7 2/3, y = 1 1/3 and z = 5 1/3.
Step-by-step explanation:
2x+4y+3z=6 ..... 1
x-2y+z=-5 ...... 2
-x-3y-2z=-7 .......3
Add equations 2 and 3 to eliminate x:
-5y - z = -12 .....4
Multiply equation 2 by - 2:
-2x + 4y - 2z = 10
Add this to equation 1:
8y + z = 16 ........ 5
Now add equation 4 to equation 5:
3y = 4
y = 4/3 = 1 1/3.
Now find z by substituting for y in equation 4:
-5(4/3) - z = -12
z = 12 - 20/3
z = 36/3 - 20/3 = 16/3 = 5 1/3.
Finally, we find x by substituting for y and z in equation 1:
2x + 4*4/3 + 3*16/3 = 6
2x = 6 - 16/3 - 16
2x = 18/3 - 16/3 - 48/3 = -46/3
x = 23/3 = 7 2/3.
Here are your answers: Renting: 1. When you rent something you will have for a good amount of time. 2. When you rent something you have control over it since you rented it with your money. Buying: 2, You get to keep it forever. 3. you can sell it for more so you can make a profit to buy something else.
