complete the following system of equations grafically.

x+y=0
-3x+4y=14

1 answer

To solve the system of equations graphically, we need to plot each equation on a coordinate plane.

  1. Equation 1: \(x + y = 0\)

    • This can be rewritten as \(y = -x\).
    • This is a straight line that passes through the origin (0, 0) and has a slope of -1.
    • Two points on this line are:
      • When \(x = 0\), \(y = 0\) (point: (0, 0)).
      • When \(x = 4\), \(y = -4\) (point: (4, -4)).
  2. Equation 2: \(-3x + 4y = 14\)

    • This can be rewritten as \(4y = 3x + 14\) or \(y = \frac{3}{4}x + \frac{14}{4}\) or \(y = \frac{3}{4}x + 3.5\).
    • This is a straight line with a slope of \(\frac{3}{4}\) and a y-intercept of 3.5.
    • Two points on this line can be found:
      • When \(x = 0\), \(y = 3.5\) (point: (0, 3.5)).
      • When \(x = 4\), \(y = \frac{3}{4}(4) + 3.5 = 3 + 3.5 = 6.5\) (point: (4, 6.5)).

Now, we can plot these points on the coordinate plane:

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

    • Plot (0, 0) and (4, -4), and draw the line through these points.
  • For the second equation \(y = \frac{3}{4}x + 3.5\):

    • Plot (0, 3.5) and (4, 6.5), and draw the line through these points.

Now, where the two lines intersect is the solution to the system of equations.

Solution:

When you plot these two lines on a graph, they will intersect at a single point. The coordinates of that intersection point will give you the solution to the system of equations.

To find the exact intersection point algebraically, you can solve the system.

  1. From \(x + y = 0\), we get \(y = -x\).

  2. Substitute \(y\) into the second equation:

    \[ -3x + 4(-x) = 14 \] \[ -3x - 4x = 14 \] \[ -7x = 14 \implies x = -2 \]

  3. Substitute \(x = -2\) back into \(y = -x\):

    \[ y = -(-2) = 2 \]

Thus, the solution to the system of equations is \( (x, y) = (-2, 2) \).

Summary:

  • The equations are \(x + y = 0\) and \(-3x + 4y = 14\).
  • The intersection point, found graphically and verified algebraically, is \((-2, 2)\).