bonjour,
soit x la longueur et y la largeur
P = 2x+2y = 110
on simplifie : x+y = 55
on augmente x de 1 = (x+1)
on diminue y de 1 = (x-1)
et l'aire diminue de 4m² = (x+1)(y+1) = xy-4
x+y = 55
(x+1)(y-1) = xy-4
x+y = 55
xy-x+y-1 =xy-4
x+y = 55
xy-x+y-xy = -4+1
x+y = 55
-x+y = -3
2y = 52
y = 26
x+y = 55
x = 29
Longueur = 29
largeur = 26
Aire initiale = 29*26 = 754m²
Aire apres = (29+1)(26-1) = 30*25 = 750m²
on a la ≠ de 4m²
