I would multiply 4/7 by 5 and 3/5 by 7 to get 20/35 and 21/35. The Least Common factor is 35
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).
Answer:
can u make. the question more clear how can I find the answer when both are in km?
270.166 repeating is the answer
The correct answer is A, smaller than the size you started with. Because you increased the size by 30% of the original page, and then took 30% of the larger page, you're taking more away than you increased it by. For instance, if you had a page that was 60 units², and you increased it by 30% (18 units), you would get 78 units². However, if you took 30% of 78 (23.4) and subtracted it, you would get 54.6 units², which is smaller than 60 units².
Hope this helps!
