1º) Réduire ( w+5 ) ( y+2) -wy
wy+2w+5y+10-wy =
2w+5y+10
2) P = 2x+2y
x = L
y = l
330 = 2y+2y
on peut simplifie rpar 2 :
x+y = 165
Aire initiale = xy
on augmente :
(x+5)(y+2) = xy+460
on a le systeme :
x+y = 165
(x+5)(y+2) = xy+460
x+y = 165
xy+2x+5y+10 = xy+460
x+y = 165
xy-xy+2x+5y = 460-10
x+y = 165
2x+5y = 450
x =-y+165
2(-y+165)+5y = 450
-2y+330+5y = 450
-2y+5y = 450-330
3y = 120
y = 40
x+y = 165
x= -40+165
x = 125
L = 125
l = 40