# Answer to Question #21385 in Algebra for lara

Question #21385

wall paper,312 cm long and 25 cm wide is required to cover the walls of a room. length of the room is 7 m and its breadth is twice height.determine the height of the room.

Expert's answer

We assume, that room doesn't have any windows and doors.

For paper S=312*25

For walls S=2*(l+b)*h

l=700 sm

b=2h

2*(700+2h)h=312*25

4h^2+700h-7800=0

h^2+125h-1800=0

Hence, h=13 sm

So, we see, that input data are not right.

If we will take wall paper 3120 sm length, we get h=185 sm, that is normal result.

For paper S=312*25

For walls S=2*(l+b)*h

l=700 sm

b=2h

2*(700+2h)h=312*25

4h^2+700h-7800=0

h^2+125h-1800=0

Hence, h=13 sm

So, we see, that input data are not right.

If we will take wall paper 3120 sm length, we get h=185 sm, that is normal result.

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