A linear function has a slope of Negative StartFraction 7 Over 9 EndFraction and a y-intercept of 3. How does this function compare to the linear function that is represented by the equation y + 11 = Negative StartFraction 7 Over 9 EndFraction (x minus 18)?

It has the same slope and the same y-intercept.
It has the same slope and a different y-intercept.
It has the same y-intercept and a different slope.
It has a different slope and a different y-intercept.

1 answer

Let's analyze the two linear functions given in the problem.

  1. The first linear function is represented in slope-intercept form \( y = mx + b \), where \( m \) is the slope and \( b \) is the y-intercept.

    • For the first function, the slope is \(-\frac{7}{9}\) and the y-intercept is \(3\).
    • Therefore, the equation of the first linear function can be written as: \[ y = -\frac{7}{9}x + 3 \]
  2. The second function is given by the equation: \[ y + 11 = -\frac{7}{9}(x - 18) \] We need to put this in slope-intercept form. Let's first expand and rearrange it: \[ y + 11 = -\frac{7}{9}x + \frac{7}{9} \cdot 18 \] \[ y + 11 = -\frac{7}{9}x + 14 \] Now isolate \(y\): \[ y = -\frac{7}{9}x + 14 - 11 \] \[ y = -\frac{7}{9}x + 3 \]

Now that we have both functions:

  • The first function is \( y = -\frac{7}{9}x + 3 \).
  • The second function is also \( y = -\frac{7}{9}x + 3 \).

From this, we can see that both functions have the same slope of \(-\frac{7}{9}\) and the same y-intercept of \(3\).

Therefore, the correct comparison is: It has the same slope and the same y-intercept.