It looks like the differential equation is

Check for exactness:

As is, the DE is not exact, so let's try to find an integrating factor <em>µ(x, y)</em> such that

*is* exact. If this modified DE is exact, then

We have

Notice that if we let <em>µ(x, y)</em> = <em>µ(x)</em> be independent of <em>y</em>, then <em>∂µ/∂y</em> = 0 and we can solve for <em>µ</em> :

The modified DE,

is now exact:

So we look for a solution of the form <em>F(x, y)</em> = <em>C</em>. This solution is such that

Integrate both sides of the first condition with respect to <em>x</em> :

Differentiate both sides of this with respect to <em>y</em> :

Then the general solution to the DE is

I think the answer for this question is the second one
0.89
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Answer:
a. Blue
Step-by-step explanation:
The answer is blue because there are still more blue than green and the ratio is 7:6. So the probability is the second ball removed is a blue ball. Hope this helps :)
There are 8 sets of 21 cups in 168 cups so 9 times 8 is 72