Question

Zece cozonaci cu nuca si opt cozonaci cu stafide cantaresc 26 kg . sapte cozonaci cu nuca si zece cozonaci cu stafide cantaresc 27 kg. Cat cantareste un cozonac din fiecare fel ?

Answer 1

10a+8b=26|•7=>70a+56b=182; 7a+10b=27|•10=>70a+100b=270; 270-182=44b; 88=44b; b=88/44=2kg; a=(26-8•2)/10=10/10=1kg

Answer 2

10c.n+8c.s=26kg
 7c.n+10c.s=27kg
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17+18=35 c. n.si s.

17cn++18c.s=53kg

10+7=17c.n
8+10=18c.s
18-17=1 c.n mai putin27-26=1kg dif.intre cantitatile de cozonaci

=> 1c.n=1kg.

17 x1=17 c.n => 17x1=17kg c.n
1+1=2kg c.s
18x2=36 kg.c.s

17+18=35 c.
17+36=53kg c(n+s)

deci (10c.n x 1kg )+(8c.s x 2kg)=10kg+16kg=26kg.c( n+s)
        ( 7c.n x 1kg)+(10c.s x 2kg)= 7kg+20kg=27kg.c(n+s)
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         (17c.n x1 kg)+18c.s x2kg)=17kg+36kg=53kg.c(n+s)

R=>cozonacul cu nuca cantareste 1kg.
      cozonacul cu stafide cantareste 2kg.