Resposta :
[tex]\Large\boxed{\begin{array}{l}\sf 2y^2=7y\\\sf 2y^2-7y=0\\\sf y\cdot(2y-7)=0\\\sf y=0\\\sf 2y-7=0\\\sf 2y=7\\\sf y=\dfrac{7}{2}\\\sf S=\bigg\{0,\dfrac{7}{2}\bigg\}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~c}}}}\end{array}}[/tex]