P=300m
P=2 L+2 l
a)L=105 m
300m=2x105m+2 l
300m=210+2 l
2 l=300-210m
2l=90m
l=90/2
l=45 m
b)L= l+30m
2x(l+30m)+2 l=300m
2 l+60m+2 l=300m
4 l=300-60m
4 l=240m
l=240/4
l=60m
L=60m+30m
L=90m
2x90m+2x60m=300m
180m+120m=300m
c) l=1/4din L
l=L/4
2xL+2x(L/4)=300m
2L+2L/4=300m
2L+L/2=300m unde 2/4=1/2
aducem l;a acelasi numitor
4L+L=300mx2
5L=600m
L=600m/5
L=120m
l=120/4
l=30m
2x120m+2x30m=300m
240m+60m=300m
l=latimea,L=lungimea
