Răspuns:
a + b + c = 71.459
a, b, c = ?
a + b = 39.033
b + c = 56.034
a = 39.033 - b
39.033 - b + b + c = 71.459
39.033 + c = 71.459
c = 71.459 - 39.033
c = 32.426
b + c = 56.034
b + 32.456 = 56.034
b = 56.034 - 32.456
b = 23.578
a + b = 39.033
a + 23.578 = 39.033
a = 39.033 - 23.578
a = 15.455