Question

The length of a rectangle is 8 metre less than that tries is breadth if area of a rectangle is 16 square metre then the find the length and breadth of the rectangle

Answer 1

let l m be length and b m be breadth.

given that,

l = 3b-8------------(1)

area of rectangle = l*b

but given area =16 square m.

i.e. l*b= 16

from (1)

(3b-8)*b=16

3b2-8b=16

3b2-8b-16=0

3b2-12b+4b-16=0

3b(b-4)+4(b-4)=0

(3b+4) and (b-4)

zeroes are either b= -4/3  or b=4

consider b=4m

then put b=4m in (1)

l=3*4-8

l=12-8

l=4m

hence length =4m and breadth =4m

to verify area of rectangle i.e l*b=16 square m

and 4*4=16 square metre

hence verifed