1)
a + b = 252
a = b + 42
a |______|+42
b |______|
252 - 42 = 210
210 : 2 = 105 (un segment egal)
a = 105+42 = 147
b = 105
V. 147+105 = 252
2)
a-b =28 ==> a = b + 28
a+b=490
a |_______|+28
b |_______|
490 - 28 = 462
462 : 2 = 231 (un segment egal)
a = 231 + 28 = 259
b = 231
V. 259 + 231 = 490
259 - 231 = 28
