Question

A rectangular living room has a perimeter of 30 meters. Its area is 50 square meters. What are the dimensions of the living room?

Answer 1

The one of (L,b)= (5m, 10m) is the only correct answer.

Explanation:

P= 2(L+b)

A= L×b

make b subject of formula in area we have;

b= A/L

in perimeter; p= 2(L +(A/L))

p= (L²+A)/L

pL= L²+A

L²-pL+A= 0

L²-30L+50=0

L²-25L-5L+50=0

L(L-25)-5(L-25)=0

(L-5)(L-25)= 0

L= 5 or 25m

substitute in A

50= 5b or 50= 25b

b= 10 or 2m