Question

Find the dimensions of arectangle whose perimeter is 28meters and whose area is 40 square meters.

Answer 1

2(l+b)=28⇒l+b=14⇒l=14-b
lb=40..................(1)
l value in (1)
14-b×b=40
14b-b²=40
b²-14b+40=0
b=4,b=10
l=10,l=4