A geometry class is asked to find the equation of a line that is parallel to [tex]\( y - 3 = -(x + 1) \)[/tex] and passes through [tex]\((4, 2)\)[/tex].

Trish states that the parallel line is [tex]\( y - 2 = -1(x - 4) \)[/tex].

Demetri states that the parallel line is [tex]\( y = -x + 6 \)[/tex].

Are the students correct? Explain.

A. Trish is the only student who is correct; the slope should be -1, and the line passes through [tex]\((4, 2)\)[/tex].

B. Demetri is the only student who is correct; the slope should be -1, and the [tex]\( y \)[/tex]-intercept is 6.

C. Both students are correct; the slope should be -1, passing through [tex]\((4, 2)\)[/tex] with a [tex]\( y \)[/tex]-intercept of 6.

D. Neither student is correct; the slope of the parallel line should be 1.



Answer :

To determine whether the students are correct, we need to determine the correct equation of a line that is parallel to [tex]\( y - 3 = -(x + 1) \)[/tex] and passes through the point [tex]\((4, 2)\)[/tex].

1. Identify the Slope of the Given Line:
The provided line equation is [tex]\( y - 3 = -(x + 1) \)[/tex]. First, let's rewrite it in the slope-intercept form [tex]\( y = mx + b \)[/tex]:

[tex]\[ y - 3 = -x - 1 \implies y = -x + 2 \][/tex]

So, the slope [tex]\( m \)[/tex] of the given line is [tex]\( -1 \)[/tex].

2. Parallel Line Equation:
For a line to be parallel to another, it must have the same slope. Therefore, the slope of the line we are looking for should also be [tex]\( -1 \)[/tex].

3. Equation of the Parallel Line Through a Given Point:
We need the equation of a line with slope [tex]\( -1 \)[/tex] that passes through the point [tex]\((4, 2)\)[/tex]. We can use the point-slope form of a line equation, which is [tex]\( y - y_1 = m(x - x_1) \)[/tex]:

[tex]\[ y - 2 = -1(x - 4) \][/tex]

4. Trish's Line:
Let's simplify Trish's equation [tex]\( y - 2 = -1(x - 4) \)[/tex] to verify it:

[tex]\[ y - 2 = -x + 4 \implies y = -x + 6 \][/tex]

Trish simplifies and concludes that is the equation of the parallel line going through the point.

5. Demetri's Line:
Demetri stated the equation directly as [tex]\( y = -x + 6 \)[/tex].

6. Check if Both Lines Pass Through (4, 2):
Now, let's check whether the point [tex]\((4, 2)\)[/tex] satisfies both equations [tex]\(y = -x + 6\)[/tex]:

For [tex]\( x = 4 \)[/tex]:

[tex]\[ y = -4 + 6 = 2 \][/tex]

The point [tex]\((4, 2)\)[/tex] indeed lies on the line [tex]\( y = -x + 6 \)[/tex].

Conclusion:
Both the equations given by Trish and Demetri are correct:
- Trish correctly converted her point-slope form equation into slope-intercept form.
- Demetri directly gave the correct slope-intercept form.

Thus, the correct conclusion is:
Both students are correct; the slope should be -1, passing through [tex]\((4, 2)\)[/tex] with a [tex]\( y \)[/tex]-intercept of 6.