the area of the four walls in a room is 120 m square the length of twice the breadth full stop if the height of the room is 4 m find the area of the floor
Answers
Answer:
=50m²
Step-by-step explanation:
Given, Area of four walls in a room = 120m²
height of room (h) = 4m
Here given that length is twice of the breadth
Then Let, breadth of room (b) = xm
length of room (l) = 2x m
we know that,
Area of room = 2(lb+bh+hl)
120 = 2 (2x*x+x*4+4*2x)
60 = 2x²+4x+8x
30 = x²+6x ⇒x²+6x-30 ⇒ x²+6x-5x-30
⇒x(x+6) -5(x+6) ,take common x+6 we get,
⇒(x+6) (x-5)
now solving this we get the vale of x=5,-6
but as we know length or breadth is not negative so we take only positive value as x.
Now, breadth of room = x = 5m
length of room = 2x = 2*5 = 10
Now area of floor = length*breadth = 10*5 = 50m²