Question

8a+7b=249 si 5a+6b=193 cat face a+b?

Answer 1

8a+7b=249

5a+6b=193

din aceste 2 ecuatii prin scadere rezulta 3a+b=56, apoi rezulta ca b=56-3a

5a+6x(56-3a)=193

5a+336-18a=193

336-193=18a-5a

123=13a

a=123:13=11

b=56-3x11

b=56-33=23

a+b=11+23=34