Question

5 caise si 4 piersici cântăresc 880g, iar 2 caise si 3 piersici cântăresc 520g. Cât cântăresc 3 caise si 5 piersici?​

Answer 1

5c + 4p = 880

2c + 3p = 520 => 2c = 520 - 3p => c = (520 - 3p)/2

inlocuim

5(520-3p)/2 + ²4p = ²880

2600 - 15p + 8p = 1760

2600 - 1760 = 15p - 8p

840 = 7p

p = 840 : 7

p = 120 grame

c = (520-3·120)/2

c = 80 grame

• 3c + 5p = 3·80g + 5·120g = 240g + 600g = 840 grame

Answer 2

Răspuns:

5 caise....4 piersici....880g+

2 caise....3 piersici....520g

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7c+7p=880+520

7(c+p)=1400=>c+p=1400:7=>c+p=200 g=>c=200-p

5c+4p=880

5(200-p)+4p=880

1000-5p+4p=880

p=1000-880=>p=120 g cantareste o piersica

c=200-120=>c=80g cantareste o caisa

3·80+5·120=240+600=840 g cantaresc 3 caise si 5 piersici