E:16407

16407 (Cristina Vijdeluc, Salonic și Mihai Vijdeluc)

Aflați cifrele nenule Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a } și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle b} pentru care Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a + 10 \cdot (a + b)^{3} = \overline{baba}.}

Soluție:

Egalitatea din enunț se scrie Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a + 10 \cdot (a + b)^{3} = \overline{bab0} + a,} de unde Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 10 \cdot (a + b)^{3} = \overline{bab0} } și apoi $(a+b)^{3}={\overline {bab}}.$ Căutând prin încercări cuburi perfecte de 3 cifre, găsim $7^{3}=343$. Astfel, $a=4$ și $b=3$, de unde ${\overline {ab}}=43.$