Question

se stie ca a+2b+c=51 si 2a+b+2c=42 aflati a+b+c . trg faceți mai repde​

Answer 1

Răspuns:

Explicație pas cu pas:

a+2b+c= 51  l x2

2a+b+2c=42

-

2a+4b+2c= 102

2a+b+  c=    42

4b-b= 60

3b=60

b= 60 :3

b= 20

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2a+4*20+2c= 102

2a+80+2c= 102

2a+2b=102-80

2a+2b= 22

2*(a+b)=22

a+b=22:2

a+b=11

a+b+c= 11+20

-

a+b+c= 31