Question

Which of the following accurately shows the first step whensolving the following system of equations by substitution?

Answer 1

Step-by-step explanation

The method of substitution consists of 3 steps:

0. Solve one equation for one of the variables.

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1. Substitute the expression into the other equation and solve.

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2. Resubstitute the value into the original equation to find the corresponding variable.

In this case, we have the system of equations:

`\begin{cases}y=-5x^2+2x+7\Rightarrow\text{ Equation 1} \\ y={-3x+4\Rightarrow\text{ Equation 2}}\end{cases}`

As we can see, the first step is done.

Then, for the next step, we can substitute the value of y from Equation 1 in Equation 2.

`\begin{gathered} \begin{equation*} y=-3x+4 \end{equation*} \\ -5x^2+2x+7=-3x+4 \end{gathered}`Answer

The first step in solving the given system of equations by substitution is:

`-5x^(2)+2x+7=-3x+4`