Question

Află cifra A daca a+a×a+a×a=9a​

Answer 1

Răspuns:

    $\text{S}=\{0;4\}$

Explicație pas cu pas:

    $a+a*a+a*a=9a\\\\a+a^2+a^2=9a\\\\2a^2-8a=0\\\\2a(a-4)=0 \iff 2a=0 \iff a_{1}=0\\~~~~~~~~~~~~~~~~~~~ \iff a-4=0 \iff a_{2}=4\\\\\boxed{\boxed{\text{S}=\{0;4\}}}$