Resposta:

[tex]\textsf{Leia abaixo}[/tex]

Explicação passo a passo:

[tex]\sf{ax^2 + bx + c = 0}[/tex]

[tex]\sf{2x^2 - 7x - 15 = 0}\rightarrow\begin{cases}\sf{a = 2}\\\sf{b = -7}\\\sf{c = -15}\end{cases}[/tex]

[tex]\sf{\Delta = b^2 - 4.a.c}[/tex]

[tex]\sf{\Delta = (-7)^2 - 4.2.(-15)}[/tex]

[tex]\sf{\Delta = 49 + 120}[/tex]

[tex]\sf{\Delta = 169}[/tex]

[tex]\sf{x = \dfrac{-b \pm \sqrt{\Delta}}{2a} = \dfrac{7 \pm \sqrt{169}}{4} \rightarrow \begin{cases}\sf{x' = \dfrac{7 + 13}{4} = \dfrac{20}{4} = 5}\\\\\sf{x'' = \dfrac{7 - 13}{4} = -\dfrac{6}{4} = -\dfrac{3}{2}}\end{cases}}[/tex]

[tex]\boxed{\boxed{\sf{S = \left\{5\:,\dfrac{3}{2}\right\}}}}\leftarrow\textsf{letra E}[/tex]