3. Two sidewalks in a park are represented by lines on a coordinate grid. Two points on each of the lines are shown in the tables below.

Sidewalk 1
\begin{tabular}{|c|c|}
\hline [tex]$x$[/tex] & [tex]$y$[/tex] \\
\hline 2 & 7 \\
\hline 0 & 3 \\
\hline
\end{tabular}

Sidewalk 2
\begin{tabular}{|c|c|}
\hline [tex]$x$[/tex] & [tex]$y$[/tex] \\
\hline 1 & 5 \\
\hline 3 & 3 \\
\hline
\end{tabular}

(a) Write the equation for Sidewalk 1 in slope-intercept form.

(b) Write the equation for Sidewalk 2 in point-slope form and then in slope-intercept form.

(c) Is the system of equations consistent, independent, coincident, or inconsistent? Explain.

(d) If the two sidewalks intersect, what are the coordinates of the point of intersection? Use the substitution method and show your work.

Answer:



Answer :

Let's tackle this problem step by step.

### (a) Write the equation for Sidewalk 1 in slope-intercept form

1. Identify the given points:
- The points given for Sidewalk 1 are (2, 7) and (0, 3).

2. Calculate the slope [tex]\( m \)[/tex]:
The formula for the slope between two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]
Substituting the values:
[tex]\[ m = \frac{3 - 7}{0 - 2} = \frac{-4}{-2} = 2 \][/tex]

3. Determine the y-intercept [tex]\( b \)[/tex]:
Use the slope-intercept form [tex]\( y = mx + b \)[/tex] and one of the points [tex]\((x_1, y_1)\)[/tex].
Substituting [tex]\( m = 2 \)[/tex], [tex]\( x_1 = 2 \)[/tex], and [tex]\( y_1 = 7 \)[/tex]:
[tex]\[ 7 = 2 \cdot 2 + b \implies 7 = 4 + b \implies b = 3 \][/tex]

4. Write the equation:
The slope-intercept form equation is:
[tex]\[ y = 2x + 3 \][/tex]

### (b) Write the equation for Sidewalk 2 in point-slope form and then in slope-intercept form

1. Identify the given points:
- The points given for Sidewalk 2 are (1, 5) and (3, 3).

2. Calculate the slope [tex]\( m \)[/tex]:
Using the slope formula:
[tex]\[ m = \frac{3 - 5}{3 - 1} = \frac{-2}{2} = -1 \][/tex]

3. Write the point-slope form equation:
The point-slope form of the equation is:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]
Using point [tex]\((1, 5)\)[/tex] and slope [tex]\( m = -1 \)[/tex]:
[tex]\[ y - 5 = -1(x - 1) \implies y - 5 = -x + 1 \][/tex]

4. Convert to slope-intercept form:
Solving for [tex]\( y \)[/tex]:
[tex]\[ y = -x + 1 + 5 \implies y = -x + 6 \][/tex]

### (c) Is the system of equations consistent, independent, coincident, or inconsistent? Explain

1. Compare the slopes and y-intercepts of the two lines:
- Equation for Sidewalk 1: [tex]\( y = 2x + 3 \)[/tex]
- Equation for Sidewalk 2: [tex]\( y = -x + 6 \)[/tex]

2. Determine the relationship:
- The slopes are different ([tex]\(2\)[/tex] and [tex]\(-1\)[/tex]).
- Since the slopes are different, the lines are neither parallel nor coincident.

3. Conclusion:
- Since the slopes are different, the lines will intersect at exactly one point.
- Therefore, the system of equations is consistent and independent.

### (d) If the two sidewalks intersect, what are the coordinates of the point of intersection? Use the substitution method and show your work

1. Set the equations equal to each other:
[tex]\[ 2x + 3 = -x + 6 \][/tex]

2. Solve for [tex]\( x \)[/tex]:
[tex]\[ 2x + x = 6 - 3 \implies 3x = 3 \implies x = 1 \][/tex]

3. Substitute [tex]\( x = 1 \)[/tex] back into one of the equations to find [tex]\( y \)[/tex]:
Using the equation [tex]\( y = 2x + 3 \)[/tex]:
[tex]\[ y = 2(1) + 3 = 2 + 3 = 5 \][/tex]

4. Coordinate of the intersection point:
The two sidewalks intersect at the point [tex]\((1, 5)\)[/tex].

To summarize:
(a) The equation for Sidewalk 1 in slope-intercept form is [tex]\( y = 2x + 3 \)[/tex].

(b) The equation for Sidewalk 2 in point-slope form is [tex]\( y - 5 = -1(x - 1) \)[/tex], which converts to [tex]\( y = -x + 6 \)[/tex] in slope-intercept form.

(c) The system of equations is consistent and independent.

(d) The coordinates of the point of intersection are [tex]\((1, 5)\)[/tex].