Solve the following system of equations algebraically:

y, equals, x, squared, minus, 2, x, minus, 1
y=
x
2
−2x−1
y, equals, 3, x, minus, 1
y=
3x−1

1 answer

To solve the system of equations algebraically, we start with the two equations provided:

  1. \( y = x^2 - 2x - 1 \)
  2. \( y = 3x - 1 \)

Since both equations are equal to \( y \), we can set them equal to each other:

\[ x^2 - 2x - 1 = 3x - 1 \]

Next, we can move all terms to one side of the equation. First, we will subtract \( 3x \) and add \( 1 \) to both sides:

\[ x^2 - 2x - 1 - 3x + 1 = 0 \]

This simplifies to:

\[ x^2 - 5x + 0 = 0 \]

Factoring the equation:

\[ x(x - 5) = 0 \]

Setting each factor to zero gives us the solutions for \( x \):

  1. \( x = 0 \)
  2. \( x = 5 \)

Now, we will find the corresponding \( y \) values for each \( x \).

For \( x = 0 \):

Substituting into the second equation:

\[ y = 3(0) - 1 = -1 \]

So one solution is \( (0, -1) \).

For \( x = 5 \):

Substituting into the second equation:

\[ y = 3(5) - 1 = 15 - 1 = 14 \]

So the other solution is \( (5, 14) \).

Thus, the solutions to the system of equations are:

\[ (0, -1) \quad \text{and} \quad (5, 14) \]