{14a+8b=86lei /(-3) o amplific cu -3
22a+24b=158lei
{-42a-24b=-258
22a+24b=158
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-20a = -100; a=-100/-20; a=5, deci un kg de banane = 5lei
inlocuiesc in prima: 14*5+8b=86lei; 70 +8b=86 lei; 8b=86-70; 8b=16; b=16/8; b=2, adica 1kg portocale= 2lei
tie iti cere cat coasta 3a+1b=?;
3*5 + 2*1 = 15+ 2 = 17lei