Given the function [tex]f(x) = \frac{1}{3} x + 3[/tex]:

A design engineer is mapping out a new neighborhood with parallel streets. If one street passes through [tex]\((4, 5)\)[/tex] and [tex]\((3, 2)\)[/tex], what is the equation for a parallel street that passes through [tex]\((2, -3)\)[/tex]?



Answer :

To determine the equation of a line that is parallel to the street passing through the points [tex]\((4,5)\)[/tex] and [tex]\((3,2)\)[/tex] and also passes through the point [tex]\((2,-3)\)[/tex], we need to follow these steps:

1. Find the slope of the given street:

The slope (m) of a line through two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] can be calculated using the formula:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]
Using the points [tex]\((4,5)\)[/tex] and [tex]\((3,2)\)[/tex]:
[tex]\[ m = \frac{2 - 5}{3 - 4} = \frac{-3}{-1} = 3 \][/tex]

Therefore, the slope of the line passing through [tex]\((4,5)\)[/tex] and [tex]\((3,2)\)[/tex] is 3.

2. Identify the slope of the parallel line:

Parallel lines have the same slope. Therefore, the slope of the parallel line passing through the point [tex]\((2,-3)\)[/tex] is also 3.

3. Determine the y-intercept (b) of the parallel line:

Use the slope-intercept form of the linear equation, which is:
[tex]\[ y = mx + b \][/tex]
Substitute the slope (m = 3) and the coordinates of the point [tex]\((2, -3)\)[/tex] into the equation to find the y-intercept ([tex]\(b\)[/tex]):
[tex]\[ -3 = 3(2) + b \][/tex]
Simplify the equation:
[tex]\[ -3 = 6 + b \][/tex]
Solving for [tex]\(b\)[/tex]:
[tex]\[ b = -3 - 6 \][/tex]
[tex]\[ b = -9 \][/tex]

4. Write the equation of the parallel street:

Now that we have the slope ([tex]\(m = 3\)[/tex]) and the y-intercept ([tex]\(b = -9\)[/tex]), we can write the equation of the parallel street in slope-intercept form:
[tex]\[ y = 3x - 9 \][/tex]

Thus, the equation of the parallel street that passes through the point [tex]\((2, -3)\)[/tex] is:
[tex]\[ \boxed{y = 3x - 9} \][/tex]