1.x-varsta elevei
y-varsta fratelui
x-2=3(y-2)
x-2=3y-6
x=3y-6+2
x=3y-4
x+1=2(y+1)
x+1=2y+2
x=2y+2-1
x=2y+1
3y-4=2y+1
3y-2y=1+4
y=5
x=2*5+1=10+1=11
2)261,42*1,4=365,988 -a parcurs in a2a zi
261,42+365,988=627,408- a parcurs in primele 2 zile
627,408-512,43=114,978- a parcurs in a3a zi
627,408+114,978=742,386-a parcurs in primele 3 zile
897,23-742,386=154,844-a parcurs in a4a zi