3.8 The value of $y$ that satisfies the equations $2 x^{2}+6 x+5 y+1=0$ and $2 x+y+3=0$ satisfies the equation
(A) $y^{2}+14 y-7=0$.
(B) $y^{2}+8 y+1=0$.
(C) $y^{2}+10 y-7=0$.
(D) $y^{2}+y-12=0$.
(E) None of the above answers is correct.
(1st American High School Mathematics Examination, 1950)
[Solution] Solving for $x$ from the second equation and substituting it into the first equation, we get:
$$
\begin{array}{c}
2\left(-\frac{y+3}{2}\right)^{2}+6\left(-\frac{y+3}{2}\right)+5 y+1=0, \\
y^{2}+10 y-7=0 .
\end{array}
$$

Therefore, the correct choice is (C).