Estimate the solution to the system of these linear equations based on the graph.

2x-y=-4
x-y=-1

1 answer

To estimate the solution to the system of linear equations given by:

  1. \( 2x - y = -4 \)
  2. \( x - y = -1 \)

we can first rewrite each equation in slope-intercept form (\(y = mx + b\)), which makes it easier to graph and find their intersection.

For the first equation \( 2x - y = -4 \):

Rearranging gives:

\[ y = 2x + 4 \]

For the second equation \( x - y = -1 \):

Rearranging gives:

\[ y = x + 1 \]

Now, let's graph the equations:

  1. Graph of \( y = 2x + 4 \):

    • When \( x = 0 \), \( y = 4 \) (y-intercept).
    • When \( x = -2 \), \( y = 0 \) (x-intercept).
    • The line will slope upwards, crossing the y-axis at 4.
  2. Graph of \( y = x + 1 \):

    • When \( x = 0 \), \( y = 1 \) (y-intercept).
    • When \( x = -1 \), \( y = 0 \) (x-intercept).
    • The line will also slope upwards, crossing the y-axis at 1.

Finding the intersection point:

The solution to the system of equations is the point where these two lines intersect.

To find this point algebraically, we can set the two equations equal to each other:

\[ 2x + 4 = x + 1 \]

Subtract \(x\) from both sides:

\[ 2x - x + 4 = 1 \]

Simplifying gives:

\[ x + 4 = 1 \]

Then we subtract 4 from both sides:

\[ x = 1 - 4 = -3 \]

Plugging \(x\) back in to find \(y\):

We can substitute \(x = -3\) into either equation; let's use \(y = x + 1\):

\[ y = -3 + 1 = -2 \]

Conclusion:

Therefore, the estimated solution to the system of equations \(2x - y = -4\) and \(x - y = -1\) is:

\[ \boxed{(-3, -2)} \]