Answer :
We start with the system of equations:
[tex]$$
\begin{cases}
y = 3x^3 - 7x^2 + 5, \\
y = 7x^4 + 2x.
\end{cases}
$$[/tex]
Since both expressions are equal to [tex]$y$[/tex], we set them equal to each other:
[tex]$$
3x^3 - 7x^2 + 5 = 7x^4 + 2x.
$$[/tex]
This is the equation that is solved by the given system of equations. Therefore, the correct answer is the equation:
[tex]$$
3x^3 - 7x^2 + 5 = 7x^4 + 2x.
$$[/tex]
This corresponds to option 2.
[tex]$$
\begin{cases}
y = 3x^3 - 7x^2 + 5, \\
y = 7x^4 + 2x.
\end{cases}
$$[/tex]
Since both expressions are equal to [tex]$y$[/tex], we set them equal to each other:
[tex]$$
3x^3 - 7x^2 + 5 = 7x^4 + 2x.
$$[/tex]
This is the equation that is solved by the given system of equations. Therefore, the correct answer is the equation:
[tex]$$
3x^3 - 7x^2 + 5 = 7x^4 + 2x.
$$[/tex]
This corresponds to option 2.