Please explain #2 for me please! The question deals with proportions.

Mathematics

1 answer:

Ket [755]3 years ago

3 0

We claim that the ratio of the areas is (3/2)^3=27/8, not just for these lengths, but also for every possible set of side-lengths x, y, and z.

To find the volume of the area of the original suitcase, multiply together x, y, and z to get xyz. The modified suitcase will have all these dimensions multiplied by 1 1/2, or 3/2, for a result of 3x/2*3y/x*3z/2=27xyz/8. The ratio is (27xyz/8)/(xyz)=27/8, as desired.

Note that we made no assumptions about the value of x, y, and z throughout the whole solution! Therefore, we can plug ANY side-lengths, including the problem's set (28, 16, 8) into this problem to achieve the same ratio.

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The raised vegetable garden in Susan's yard is in the shape of a rectangular prism with a volume of 48 cubic feet and a height o

Anna11 [10]

The correct question is
The raised vegetable garden in Susan's yard is in the shape of a rectangular prism with a volume of 48 cubic feet and a height of 3/4 foot. The base of the rectangular prism is not a square and the width is greater than 2 feet. What is the length and width of the rectangular prism?

let
x-------> the length of the base of the rectangular prism
y-------> the width of the base of the rectangular prism

we know that
volume of the prism=area of the base*height
volume=48 ft³
height of the prism=3/4 ft

area of the base=volume/height--------> 48/(3/4)---> 48*4/3----> 64 ft²

area of the base=64 ft²
area of the base=x*y
64=x*y--------> equation 1

y=x+2--------> equation 2

substitute equation 2 in equation 1
64=x*[x+2]-----> 64=x²+2x------> x²+2x-64=0

using a graph tool----> to resolve the second order equation
see the attached figure

the solution is
x=7.062 ft
y=x+2-----> y=7.062+2-----> y=9.062 ft

the answer is
the length of the base of the rectangular prism is 7.062 ft
the width of the base of the rectangular prism is 9.062 ft