Răspuns :
x+y = 10
10y + x - 10x - y = 9y - 9x = - 36 9(x-y) = 36
x-y = 4
2x = 14 x = 7 y = 3
10y + x - 10x - y = 9y - 9x = - 36 9(x-y) = 36
x-y = 4
2x = 14 x = 7 y = 3