Answer: 
Step-by-step explanation:
We apply the formula
.
Note that
. Take
and
in the formula above to get

Then the value of this expression is 
We can use the cosine addition formula again to simplify further. Decompose the fraction in the argument as:

Applying the formula with
and
we obtain

We conclude that this expression has the value 
Do you mean the slope of the line or the y-intercept
(2002-2001)/(18.75-17.60)= 0.869 =slope
y=mx + b -> 2001= 0.869 (17.60) +b -> b= 1985.7= y-intercept
Check the picture below
hmmm so, notice the arrows, if we simply multiply top and bottom of one fraction by the other's denominator, we end up with two fractions, with the same denominator
now, what can be between 49/56 and 24/56
well, 25/56, or 26/56 or 48/56 or 39/56 and so on
once the denominators are the same, is just a matter of which numerator is larger or smaller, to see who is who
(x - 7)(y - 9)
x*(y - 9) - 7*(y - 9)
x*y - x*9 - 7*y -7*(-9)
xy - 9x - 7y + 63
That's the product.
80 4
___ = ___
100 5
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