Răspuns :
[tex] \left \{ {{2x+2y=420} \atop {x=18+y}} \right. \left \{ {{x+y=210} \atop {x=18+y}} \right. \left \{ {{18+y+y=210} \atop {x=18+y}} \right. \left \{ {{2y=192} \atop {x=18+y}} \right. \left \{ {{y=96} \atop {x=18+96}} \right. \left \{ {{y=96} \atop {x=114}} \right. [/tex]
L=2xl+18
2L=4xl+36
4l+36+2l=420
6l+36=420
6l=420-36
6l=384
l=384:6
l=64 (latime)
L=2xl+18
L=2x64+18
L=128+18
L=146 (lungime)
2L=4xl+36
4l+36+2l=420
6l+36=420
6l=420-36
6l=384
l=384:6
l=64 (latime)
L=2xl+18
L=2x64+18
L=128+18
L=146 (lungime)