Explicație pas cu pas:
a+b+c=781.011
a+249.254=781.011
a= 781.011-249.254
a= 531.757
a+b=634.007
531.757+b=634.007
b=634.007- 531.757
b= 102.250
b+c=249.254
102.250+c=249.254
c=249.254-102.250
c=147.004