( a , b) × [ a , b ] = a × b
a × b = 28 × 784
daca ( a , b) = 28 atunci
a = 28m si b = 28n
28m × 28n = 28 × 784 divizam cu 28×28
m × n = 28
m = 1 n = 28 ; m = 4 n = 7 ; m = 28 n = 1
a = 28 b = 28 × 28 = 784
a = 7 × 28 = 196 b = 4 × 28 = 112
a = 784 b = 28