Question

Daca a+b=146, b+c=100 si 13a+3b+2c=1582 a=? b=? c=?

Answer 1

a+b = 146 -> a = 146-b
b+c = 100 -> c = 100-b

13a+3b+2c = 1582
13(146-b)+3b+2(100-b) = 1582
1898-13b+3b+200-2b = 1582
2098-12b = 1582
-12b = 1582-2098
-12b = -516 /*(-1)
12b = 516
b = 516/12
b = 43.

a = 146-b
a = 146-43
a = 103.

c = 100-b
c = 100-43
c = 57.


verificare : 13a+3b+2c = 13*103+3*43+2*57 = 1339+129+114 = 1339+243 = 1582. (adevarat)