Step-by-step explanation:
distance walked by him = 1/ 3 miles
time taken in doing so = 3/ 4 hrs.


Answer: The width is: " 10 in. " .
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Explanation:
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Consider a "rectangular prism".
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The formula for the Volume of a rectangular prism:
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V = L * w * h ;
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in which:
V = volume = 120 in.³ ;
L = length = 8 in.
w = width = ??
h = height = 1.5 in.
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We want to solve for "w" (width) ;
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Given the formula:
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V = L * w * h ;
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Rewrite the formula; by dividing EACH SIDE of the equation by
"(L * h)" ; to isolate "w" on one side of the equation;
and to solve for "w" ;
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→ V / (L * h) = ( L * w * h) / (L * h) ;
to get:
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→ V / (L * h) = w ;
↔ w = V / (L * h) ;
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Plug in our given values for "V", "L"; and "h"; to solve for "w" ;
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→ w = (120 in.³) / (8 in. * 1.5 in.) ;
→ w = (120 in.³) / (12 in.²) ;
→ w = (120/12) in. = 10 in.
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I don't know what method is referred to in "section 4.3", but I'll suppose it's reduction of order and use that to find the exact solution. Take

, so that

and we're left with the ODE linear in

:

Now suppose

has a power series expansion



Then the ODE can be written as


![\displaystyle\sum_{n\ge2}\bigg[n(n-1)a_n-(n-1)a_{n-1}\bigg]x^{n-2}=0](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Csum_%7Bn%5Cge2%7D%5Cbigg%5Bn%28n-1%29a_n-%28n-1%29a_%7Bn-1%7D%5Cbigg%5Dx%5E%7Bn-2%7D%3D0)
All the coefficients of the series vanish, and setting

in the power series forms for

and

tell us that

and

, so we get the recurrence

We can solve explicitly for

quite easily:

and so on. Continuing in this way we end up with

so that the solution to the ODE is

We also require the solution to satisfy

, which we can do easily by adding and subtracting a constant as needed:
Answer:
2000
Step-by-step explanation:
let the sum=x
3/5 of x=1200
x=1200×5/3=2000