What is the equation of the line containing the points [tex][tex]$(5, 2)$[/tex][/tex], [tex][tex]$(10, 4)$[/tex][/tex], and [tex][tex]$(15, 6)$[/tex][/tex]?

A. [tex]y = \frac{1}{5} x + 1[/tex]
B. [tex]y = \frac{2}{5} x[/tex]
C. [tex]y = x - 3[/tex]



Answer :

To determine the equation of the line that passes through the points [tex]\((5, 2)\)[/tex], [tex]\((10, 4)\)[/tex], and [tex]\((15, 6)\)[/tex], we need to find the slope (m) and intercept (b) of the line in the form [tex]\(y = mx + b\)[/tex].

Let's follow these steps:

1. Calculate the slope (m) of the line:
The slope between any 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]

Let's take the points [tex]\((5, 2)\)[/tex] and [tex]\((10, 4)\)[/tex]:
[tex]\[ m = \frac{4 - 2}{10 - 5} = \frac{2}{5} \][/tex]

We can verify it with the points [tex]\((10, 4)\)[/tex] and [tex]\((15, 6)\)[/tex]:
[tex]\[ m = \frac{6 - 4}{15 - 10} = \frac{2}{5} \][/tex]

Thus, the slope [tex]\(m\)[/tex] of the line is [tex]\(\frac{2}{5}\)[/tex].

2. Find the y-intercept (b):
We can use the point-slope form of the line equation, [tex]\(y = mx + b\)[/tex], and any of the given points to solve for [tex]\(b\)[/tex].

Using the point [tex]\((5, 2)\)[/tex]:
[tex]\[ 2 = \frac{2}{5} \cdot 5 + b \][/tex]
[tex]\[ 2 = 2 + b \][/tex]
Solving for [tex]\(b\)[/tex] gives:
[tex]\[ b = 2 - 2 = 0 \][/tex]

Therefore, the equation of the line is:
[tex]\[ y = \frac{2}{5} x \][/tex]

3. Compare with the given options:
- Option A: [tex]\(y = \frac{1}{5}x + 1\)[/tex]
- Option B: [tex]\(y = \frac{2}{5}x\)[/tex]
- Option C: [tex]\(y = x - 3\)[/tex]

The correct equation that matches our calculated equation [tex]\(y = \frac{2}{5}x\)[/tex] is:

B. [tex]\(y = \frac{2}{5}x\)[/tex]