509,398 views
6 votes
6 votes
Use substitution to solve for the values of x and y, written as the ordered pair (x, y).A. (-8, 0)B. (0, -8)C. (8, 0)D. (0, 8)

Use substitution to solve for the values of x and y, written as the ordered pair (x-example-1
User Pursuit
by
2.7k points

1 Answer

22 votes
22 votes

To use substitution, we normally has to solve one of the equations for one of the variables and substitute it into the other equation.

In this case, both equations are already solved, so we can simply substitute.

Let's substitute the first equation into the second:


\begin{gathered} x=5y+8 \\ y=x-8 \end{gathered}
\begin{gathered} y=(5y+8)-8 \\ y=5y+8-8 \\ y=5y+0 \\ y-5y=0 \\ -4y=0 \\ y=0 \end{gathered}

Now, we can substitute y into the first equation:


\begin{gathered} x=5y+8 \\ x=5\cdot0+8 \\ x=8 \end{gathered}

So, the solution is:


(8,0)

Alternative C.

User Michael Gaylord
by
3.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.