x-prima zi.
y-a doua zi.
z-a treia zi.
x+y+z=280
x+y=182
y=29+z
Deci calculam:
x+29+z+z=280
x+29+z=182
x+29+2z=280
x+z=182-29
x+2z=280-29
x+z=153
x+2z=251 *(-1)
x+z=153
-x-2z=-251
x+z=153
x+2z=251
-z=-98
x+2z=251
z=98
x+98*2=251
z=98
x+196=251
z=98
x=251-196
z=98
x=55
z=98
Deci:
y=29+z
y=29+98
y=127.
Verificare:
55+127+98=280m.
Raspuns:In prima zi au sapat 55 de m.
In a doua zi au sapat 127 de m.
In a treia zi au sapat 98 de m.
Bafta!