Question

determina suma numerelor reale a, b si c daca a +2b+3c=38 si 6a+4b+2c=68

Answer 1

a+2b+3c=38 |-2
6a+4b+2c=68

-2a-4b-6c=-76
6a+4b-2c=68
4a /-8c=- 8 |4
a-2c=-2
a=-2 +2c

-2+2c-4b-6c=-76
6(-2+2c)+4b -2c=68

-4c-4b=-76+2
-12+12c+4b-2c=68

-4c-4b=-74
10c+4b=68+12

-4c-4b=-74
10c+4b=80
6c /=6
c=1
a=-2 + 2*1= -2+2 =0

-4*1-4b=-74
-4b=-74+4
-4b=-70
4b=70
b=70/4
b=35/2