Matematică, întrebare adresată de ranceanudaniela, 8 ani în urmă

Determinati numerele naturale de forma abc stiind ca a+2b +c=6

Răspunsuri la întrebare

Răspuns de pav38
10

Răspuns: \pink{\boxed{\bf \overline{abc}\in \big\{105;113;121;204;212;220;303;311;402;410;501;600\big\}}}

Explicație pas cu pas:

\bf ~

\bf ~\overline{abc}~numerele ~cautate

a, b, c = cifre

\bf a,b,c,~\in \{ 0,1,2,3,4,5,6,7,8,9\}

\bf a\neq 0

Analizăm în funcție de ce valoare poate lua a

\bf ~

\bf ~ I)~\blue{\underline{a = 1}} \Rightarrow 1 +2b+c=6\Rightarrow 2b+c=6-1\Rightarrow \underline{2b+c= 5}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 5 \Rightarrow\underline{c = 5} \Rightarrow \red{\boxed{\bf \overline{abc}=105}}
  • \bf Daca~\underline{b = 1} \Rightarrow2\cdot1+c= 5 \Rightarrow\underline{c = 3} \Rightarrow \red{\boxed{\bf \overline{abc}=113}}
  • \bf Daca~\underline{b = 2} \Rightarrow2\cdot2+c= 5 \Rightarrow\underline{c = 1} \Rightarrow \red{\boxed{\bf \overline{abc}=121}}

\bf ~

\bf ~ II)~ \blue{\underline{a = 2}} \Rightarrow 2 +2b+c=6\Rightarrow \underline{2b+c= 4}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 4 \Rightarrow\underline{c = 4} \Rightarrow \red{\boxed{\bf \overline{abc}=204}}
  • \bf Daca~\underline{b = 1} \Rightarrow2\cdot1+c= 4 \Rightarrow\underline{c = 2} \Rightarrow \red{\boxed{\bf \overline{abc}=212}}
  • \bf Daca~\underline{b = 2} \Rightarrow2\cdot2+c= 4 \Rightarrow\underline{c = 0} \Rightarrow \red{\boxed{\bf \overline{abc}=220}}

\bf ~

\bf ~ III)~\blue{\underline{a =3}} \Rightarrow 3 +2b+c=6\Rightarrow 2b+c=6-3\Rightarrow \underline{2b+c= 3}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 3 \Rightarrow\underline{c =3} \Rightarrow \red{\boxed{\bf \overline{abc}=303}}
  • \bf Daca~\underline{b = 1} \Rightarrow2\cdot1+c= 3 \Rightarrow\underline{c = 1} \Rightarrow \red{\boxed{\bf \overline{abc}=311}}

\bf ~

\bf ~ IV)~ \blue{\underline{a =4}} \Rightarrow 4 +2b+c=6\Rightarrow 2b+c=6-4\Rightarrow \underline{2b+c= 2}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 2 \Rightarrow\underline{c =2} \Rightarrow \red{\boxed{\bf \overline{abc}=402}}
  • \bf Daca~\underline{b = 1} \Rightarrow2\cdot1+c= 2 \Rightarrow\underline{c = 0} \Rightarrow \red{\boxed{\bf \overline{abc}=410}}

\bf~

\bf ~ V)~ \blue{\underline{a =5}} \Rightarrow 5 +2b+c=6\Rightarrow \underline{2b+c= 1}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 1 \Rightarrow\underline{c =1} \Rightarrow \red{\boxed{\bf \overline{abc}=501}}

\bf~

\bf ~ VI)~ \blue{\underline{a =6}} \Rightarrow 6 +2b+c=6\Rightarrow \underline{2b+c=6}

  • \bf Daca~\underline{b = 0} \Rightarrow2\cdot0+c= 0 \Rightarrow\underline{c =0} \Rightarrow \red{\boxed{\bf \overline{abc}=600}}

\bf ~

Numere naturale sunt ce respectă conditiile problemei sunt:\pink{\boxed{\bf \overline{abc}\in \big\{105;113;121;204;212;220;303;311;402;410;501;600\big\}}}

==pav38==

Baftă multă !

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