how many solutions

y = 3x + 6
y = -13x - 4

1 answer

To find the number of solutions to the system of equations:

  1. \( y = 3x + 6 \)
  2. \( y = -13x - 4 \)

we can set the two equations equal to each other since they both represent \( y \).

So we set:

\[ 3x + 6 = -13x - 4 \]

Now, let's solve for \( x \):

  1. Add \( 13x \) to both sides: \[ 3x + 13x + 6 = -4 \] This simplifies to: \[ 16x + 6 = -4 \]

  2. Next, subtract 6 from both sides: \[ 16x = -4 - 6 \] Which simplifies to: \[ 16x = -10 \]

  3. Finally, divide both sides by 16: \[ x = -\frac{10}{16} = -\frac{5}{8} \]

Now, we can substitute \( x = -\frac{5}{8} \) back into either of the original equations to find \( y \). Let's substitute it into the first equation:

\[ y = 3\left(-\frac{5}{8}\right) + 6 \]

Calculating this:

\[ y = -\frac{15}{8} + 6 \] Convert 6 into eighths: \[ 6 = \frac{48}{8} \] So, \[ y = -\frac{15}{8} + \frac{48}{8} = \frac{33}{8} \]

Thus, the point of intersection (the solution) is: \[ \left(-\frac{5}{8}, \frac{33}{8}\right) \]

Since we have found one unique point of intersection, the system of equations has exactly one solution.

Therefore, the answer is: 1 solution.