Răspuns :
inmultim prima relatie cu 6, iar pe a doua cu 3, apoi le adunam
6a+6b =570
3b+3c=378
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6a+9b+3c=948
6a+6b =570
3b+3c=378
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6a+9b+3c=948
6a+9b+3c=?
a+b=95
b+c=126
6a+9b+3c= 6(a+b) + 3(b+c)
6a+9b+3c=6*95+3*126
=570+378
=948
a+b=95
b+c=126
6a+9b+3c= 6(a+b) + 3(b+c)
6a+9b+3c=6*95+3*126
=570+378
=948