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:
4512.
Step-by-step explanation:
We are asked to find the number of five-card hands (drawn from a standard deck) that contain exactly three fives.
The number of ways, in which 3 fives can be picked out of 4 available fives would be 4C3. The number of ways in which 2 non-five cards can be picked out of the 48 available non-five cards would be 48C2.

We can choose exactly three fives from five-card hands in
ways.

Therefore, 4512 five card hands contain exactly three fives.
Answer: 5 dollars for every pack
Step-by-step explanation:
every 6 batteries cost 30 dollars
30÷6=5
Does this help? Let me know in the comments.
In this question we have to find the effect of doubling principal, rate or time .
First we have to check the formula which is

As we see that interest is the product of principal, rate and time. So if any of these three doubles, that is if any of these three is twice of the original value, the interest gets doubled.
SO the correct option is C.
Answer:
45
Step-by-step explanation:
first we need to make an equation so we can plug in 5hours
lets make x=hours
she makes 9$ per hour so
9x
input the amount of hours they want, 5
so 9(5)
45