martin tenia ahorado una plata nose sabe cuanto.se gasto 12 pesos, despues gato 3, luego gano la misma cantidad q tenia ahorrado . al final conto la plata y tenia 23 pesos. ¿cuanto tenia ahorado?
Tenía 19 pesos ahorrados.
Procedimiento: Despejar ("x" equivale a la cantidad de pesos que tenia ahorrados)
$${\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{12}}{\mathtt{\,-\,}}{\mathtt{3}}{\mathtt{\,\small\textbf+\,}}{\mathtt{x}} = {\mathtt{23}}$$
$${\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{3}}{\mathtt{\,\small\textbf+\,}}{\mathtt{x}} = {\mathtt{23}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12}}$$
$${\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{x}} = {\mathtt{23}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}$$
(Aquí, $${\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{x}}$$ lo interpreté como $${\mathtt{x}}{\mathtt{\,\times\,}}{\mathtt{2}}$$ ya que es lo mismo)
$${\mathtt{x}}{\mathtt{\,\times\,}}{\mathtt{2}} = {\mathtt{23}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}$$
$${\mathtt{x}} = {\frac{\left({\mathtt{23}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}\right)}{{\mathtt{2}}}}$$
$${\mathtt{x}} = {\mathtt{19}}$$
