Answer:
i dont under stand sorry i cant help sorry
I have memorized facts about fractions like these, so can tell you ...

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A fraction with 9 as a denominator is a repeating 1-digit decimal with the decimal digit being the numerator of the fraction.
A fraction with 11 as a denominator is a repeating 2-digit decimal with the two digits being 9 times the numerator of the fraction.
1/8 = 0.125, so any multiple of 1/8 is that multiple of 0.125.
Let b and s be the velocity of the boat and stream respectively....
3(b-s)=27
b-s=9
b=9+s we will use this in the second equation....
2(b+s)=30
b+s=15, now use b found above in this to get:
9+s+s=15
2s+9=15
2s=6
s=3, and since from earlier b-s=9, b=9+s so
b=12
So the speed of the boat is 12mph and the stream is 3 mph
Answer:
Step-by-step explanation:
Given is a function



Average slope of this function is change of f(x) in (-2,6)/change of x in (-2,6)
= 
By mean value theorem there exists a c such that f'(c) = -18
i.e. 
Using quadratic formula
x = 2.61, -1.277
Out of these only 2.61 lies in the given interval
c = 2.61