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Afla a,b,c,știind că:. 11a+2b+c=4030;a+b=690;b+c=1040

Răspuns :

a+b+b+c=690+1040
a+2b+c=1730

11a+2b+c=4030-
     a+2b+c=1730
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10a=2300=>a=2300:10=>a=230

b=690-230=>b=460

c=1040-460=580