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Determinati nr x stiind ca: a) 100*[25 - 5*(x-3)+2]:4= 300 b) [(x +3):200 +90]:10 -10 =0


Răspuns :

100•[25-5•(x-3)+2]:4=300 100•[20•(x-3)+2]:4=300. 100•[20•(x-3)+2]=300•4. 100•[20•(x-3)+2]=1200. 20•(x-3)+2=1200:100. 20•(x-3)+2=12. 20•(x-3)=12-2. 20•(x-3)=10. x-3=10:20. x-3=0,5. x=0,5+3. x=3,5. x=35/10 => x apartine numerelor rationale