Răspuns :
d + a = 206
d = 186 + a
186 + a + a = 206
186 + 2 a = 206
2 a = 206 - 186
2 a = 20 | : 2
a = 10 bile
d = 186 + 10
d = 196 bile
d + a = 206
d = 186 + a
186 + a + a = 206
186 + 2 a = 206
2 a = 206 - 186
2 a = 20 | : 2
a = 10 bile
d = 186 + 10
d = 196 bile