Răspuns :
x+y+z=68
x=y-5
y=x+5
x=3z
z=x:3
x+x+5+x:3=68
2x+x:3=68-5
6x:3+x:3=63
7x:3=63
x=(63·3):7
x=189:7
x=27
y=27+5=32
y=32
z=27:3
z=9
x=y-5
y=x+5
x=3z
z=x:3
x+x+5+x:3=68
2x+x:3=68-5
6x:3+x:3=63
7x:3=63
x=(63·3):7
x=189:7
x=27
y=27+5=32
y=32
z=27:3
z=9
68-5=63 63÷7=9 a=9×3=27, b=9×3+5=32, c=9 primul nr are trei seg...al doilea tot trei seg plus un adaos de 5..iar al treilea un seg.