Answer:
The one of (L,b)= (5m, 10m) is the only correct answer.
Step-by-step 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
