Asked by Anonymous
A closed box in the shape of a cuboid has dimensions x cm, y cm and 5 cm.
The volume of the box is 40 cm^3 and the external surface area is 76 cm^2.
A) use the information about the volume to find and equation connecting x and y
B) use the information about the external surface area to find another equation connecting x and y.
C) solve the equations simultaneously.
I just need help with part A and B.
Thank you.
:)
The volume of the box is 40 cm^3 and the external surface area is 76 cm^2.
A) use the information about the volume to find and equation connecting x and y
B) use the information about the external surface area to find another equation connecting x and y.
C) solve the equations simultaneously.
I just need help with part A and B.
Thank you.
:)
Answers
Answered by
Reiny
A) since V = lwh
5xy = 40
xy = 8 or y = 8/x
B)
surface area = 2xy + 2(5x) + 2(5y) = 76
xy + 5x + 5y = 38
x(8/x) + 5x + 5(8/x) = 38
8 + 5x + 40/x = 38
5x + 40/x = 30
C)
times x
5x^2 - 30x + 40 = 0
x^2 - 6x + 8 = 0
(x-4)(x-2) = 0
x = 4 or x= 2
if x=4, y=2
if x=2, y=4
or we can just say the base is 4 by 2
5xy = 40
xy = 8 or y = 8/x
B)
surface area = 2xy + 2(5x) + 2(5y) = 76
xy + 5x + 5y = 38
x(8/x) + 5x + 5(8/x) = 38
8 + 5x + 40/x = 38
5x + 40/x = 30
C)
times x
5x^2 - 30x + 40 = 0
x^2 - 6x + 8 = 0
(x-4)(x-2) = 0
x = 4 or x= 2
if x=4, y=2
if x=2, y=4
or we can just say the base is 4 by 2
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.