Answer: 64 years
Step-by-step explanation:
Let assume the dealer sold the bottle now for $P, then invested that money at 5% interest. The return would be:
R1 = P(1.05)^t,
This means that after t years, the dealer would have the total amount of:
$P×1.05^t.
If the dealer prefer to wait for t years from now to sell the bottle of wine, then he will get the return of:
R2 = $P(1 + 20).
The value of t which will make both returns equal, will be;
R1 = R2.
P×1.05^t = P(1+20)
P will cancel out
1.05^t = 21
Log both sides
Log1.05^t = Log21
tLog1.05 = Log21
t = Log21/Log1.05
t = 64 years
The best time to sell the wine is therefore 64years from now.
Step-by-step explanation:
Will bought several books that cost $ 2.50 each and received a $ 2 discount on the total bill. If he paid $ 10.50, how many books did he buy ?
2.50x - 2.00 = 10.50
2.50x = 10.50 + 2.00
2.50x = 12.50
x = 12.50/2.50
x = 5....he bought 5 books
Given:
5 bonds of face value of 1,000 that paid 5% annual interest rate.
5 bonds x 1,000 = 5,000
5,000 x 5% x 1 year = 250
The total annual interest income of James is 250. Each bond earns 50 per annum.
Answer:
Let x be the value of the house before increase
Since it's increases add 7% to the overall 100%
107/100x = 749000
x = 700000
The value of the house before increase is £700000.
Hope this helps.
You do the implcit differentation, then solve for y' and check where this is defined.
In your case: Differentiate implicitly: 2xy + x²y' - y² - x*2yy' = 0
Solve for y': y'(x²-2xy) +2xy - y² = 0
y' = (2xy-y²) / (x²-2xy)
Check where defined: y' is not defined if the denominator becomes zero, i.e.
x² - 2xy = 0 x(x - 2y) = 0
This has formal solutions x=0 and y=x/2. Now we check whether these values are possible for the initially given definition of y:
0^2*y - 0*y^2 =? 4 0 =? 4
This is impossible, hence the function is not defined for 0, and we can disregard this.
x^2*(x/2) - x(x/2)^2 =? 4 x^3/2 - x^3/4 = 4 x^3/4 = 4 x^3=16 x^3 = 16 x = cubicroot(16)
This is a possible value for y, so we have a point where y is defined, but not y'.
The solution to all of it is hence D - { cubicroot(16) }, where D is the domain of y (which nobody has asked for in this example :-).
(Actually, the check whether 0 is in D is superfluous: If you write as solution D - { 0, cubicroot(16) }, this is also correct - only it so happens that 0 is not in D, so the set difference cannot take it out of there ...).
If someone asks for that D, you have to solve the definition for y and find that domain - I don't know of any [general] way to find the domain without solving for the explicit function).
