Answer:
75c-180
420 for 8 customers
Step-by-step explanation:
Her tools cost her 180
-180
she makes 75 per customer
75c
She will make
75c-180
She gets 8 customers
75(8)-180
600-180
420
Sqrt(49)*sqrt (-1) -4 = 7i-4
$56.25
8:25 - 4:25 = 4 hours
4 hours - 1 hour for lunch = 3 hours
$18.75 x 3 = $56.25
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:
40 bottles of juice
60 bottles of water
Step-by-step explanation:
let w represent water, let j represent juice. set up a system of equations:
w+2j=140
w+j=100
isolate the w by itself on the bottom equation:
w=100-j
solve the top equation by substitution, substituting 100-j for w:
w+2j=140
100-j+2j=140
100+j=140
j=40
this means that they bought 40 bottles of juice.
to find the amount of bottles of water the bought, substitute 40 for j in either of the equations (i did it in the bottom one, because it's easier):
w=100-j
w=100-40
w=60
so, they bought 60 bottles of water.
