Ma = ( a + b + c ) : 3
37,(6) = ( a + b + c ) : 3
376 - 37 / 9 = ( a + b + c ) : 3
339 / 9 = ( a + b + c ) : 3
a + b + c = 339/9 × 3
a + b + c = 1017/9
a + b + c = 113
Ma = ( a + b ) : 2
17,5 = ( a + b ) : 2
a + b = 17,5 × 2
a + b = 35
=> c = 113 - 35 = 78
b = 4a
a + 4a = 35
5a = 35
=> a = 35 : 5 = 7
=> b = 7 × 4 = 28