493,140 views
13 votes
13 votes
Solve the system of linear equations by substitution y=3x-1 and y=x-7

User Nick Reeve
by
3.4k points

1 Answer

20 votes
20 votes

We have the system of equations:


\begin{gathered} y=3x-1 \\ y=x-7 \end{gathered}

Since we have two equations that are equal to y, we can set them equal to each other.


3x-1=x-7

Lets add 1 to both sides of the equation.


3x=x-6

Subtract x from both sides of the equation.


2x=-6

Divide both sides of the equation by 2.


x=-3

Now, we can substitute x = -3 back into either equation in order to find its corresponding y-value.


y=3(-3)-1

Simplify this equation...


\begin{gathered} y=-9-1 \\ y=-10 \end{gathered}

The solution to this system of linear equations is (-3, -10).

User Roy Reiss
by
2.7k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.