College

Which equation can be solved by using this system of equations?

[tex]
\[
\left\{
\begin{array}{l}
y=3x^3-7x^2+5 \\
y=7x^4+2x
\end{array}
\right.
\]
[/tex]

A. [tex]3x^3-7x^2+5=0[/tex]

B. [tex]3x^3-7x^2+5=7x^4+2x[/tex]

C. [tex]7x^4+2x=0[/tex]

D. [tex]7x^4+3x^3-7x^2+2x+5=0[/tex]

Answer :

To determine which equation can be solved using the given system of equations, let's analyze the system step-by-step:

The system of equations is given as:

1. [tex]\( y = 3x^3 - 7x^2 + 5 \)[/tex]
2. [tex]\( y = 7x^4 + 2x \)[/tex]

To find an equation from these that can be solved, we need to equate the two expressions that are set equal to [tex]\( y \)[/tex]. Since both are equal to [tex]\( y \)[/tex], they are equal to each other:

[tex]\[ 3x^3 - 7x^2 + 5 = 7x^4 + 2x \][/tex]

This equation corresponds to one of the options in the question:

- [tex]\( 3x^3 - 7x^2 + 5 = 7x^4 + 2x \)[/tex]

Let's now compare this with the provided options:

1. [tex]\( 3x^3 - 7x^2 + 5 = 0 \)[/tex]
2. [tex]\( 3x^3 - 7x^2 + 5 = 7x^4 + 2x \)[/tex]
3. [tex]\( 7x^4 + 2x = 0 \)[/tex]
4. [tex]\( 7x^4 + 3x^3 - 7x^2 + 2x + 5 = 0 \)[/tex]

The correct answer is option (2):

[tex]\[ 3x^3 - 7x^2 + 5 = 7x^4 + 2x \][/tex]

This is the equation obtained by setting the two expressions for [tex]\( y \)[/tex] equal to each other in the system of equations given.