Resposta :
Oie, tudo bom?
Resposta: a) 0 e 5.
[tex]x {}^{2} = 5x \\ x {}^{2} - 5x = 0 \\ x \: . \: (x - 5) = 0 \\ \boxed{x = 0} \\ x - 5 = 0 \: \: \: \: \: \: \boxed{x = 5}[/tex]
[tex]\boxed{S = \left \{0 \: , \:5 \right \}}[/tex]
Att. NLE Top Shotta