RÄspuns :
2a + 7 = 19
2a = 19 - 7
2a = 12
a = 12: 2
a = 6 - numarul
-----------------------
6 x 2 + 7 = 19
2a = 19 - 7
2a = 12
a = 12: 2
a = 6 - numarul
-----------------------
6 x 2 + 7 = 19