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2014-08-14T11:20:22+03:00
A+b+c=77

a-7=3b

b+5=c/2

b=c/2 -5 = (c-10)/2

a= 3 (c/2 -5)=  3( c-10)/2=  (3c-30)/2

(3c-30)/2 + (c-10)/2 +c =77  aducem la acelasi numitor

3c-30 +c -10 +2c = 154

6c -40=154

6c=154 +40

6c=194

c=194/6

a=(3 *194/6-30)/2=  (194/2 -30)/2=  (97-30)/2= 67/2

b= (196/6-10)/2=  (196-60)/6/2=  136/6 *1/2= 68/6= 34/3