Question

Ma ajuta cnv ? Va rog ! Dau peste 30 puncte ! Ex 8 si 9 !

Answer 1

8)l=L/4=>L=4l
P dr.=2(L+l)
P dr=200
Din ambele rezulta ca 2(L+l)=200
Voi inlocui L cu 4l
2(4l+l)=200
2•5l=200
10l=200
l=20m
L=4•20=80 m

2)P∆CDE=Pdr.ABCD/2

P∆+Pdr.=54
Voi inlocui P∆ cu P dr./2 :
Pdr.+Pdr./2=54
3•Pdr./2=54
3•Pdr.=108
P dr.=36=2(L+l)
Ldr.=2l dr.
Deci 36=2(2l+l)|:2
18=3l
l=6m
L=2•6=12m

Answer 2

8)l+L=200 2l+8l=10l l=200:10=10 L=10×4=40 9)D+T=54 D=2T T+2T=54 T=54:3=18 D=54-18=36 L=2l 2l+l=3l 6l=36 l=36:6=6 L=6×2=12