Answered

Calculate the equation of the line through the points [tex]\((-1, 1)\)[/tex], [tex]\((4, 0)\)[/tex], and [tex]\((24, -4)\)[/tex].

A. [tex]\( y = \frac{1}{5} x + \frac{4}{5} \)[/tex]

B. [tex]\( y = -\frac{1}{5} x + \frac{4}{5} \)[/tex]

C. [tex]\( y = -5 x + 4 \)[/tex]

D. [tex]\( y = 5 x + 6 \)[/tex]



Answer :

To find the equation of the line passing through the points [tex]\((-1, 1)\)[/tex], [tex]\((4, 0)\)[/tex], and [tex]\((24, -4)\)[/tex], we need to determine if these points are collinear and then derive the equation of the line. Here is a detailed, step-by-step solution:

### Step 1: Calculate the slope between the first two points [tex]\((-1, 1)\)[/tex] and [tex]\((4, 0)\)[/tex]

The formula for the slope [tex]\(m\)[/tex] 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]

For the points [tex]\((-1, 1)\)[/tex] and [tex]\((4, 0)\)[/tex]:
[tex]\[ m = \frac{0 - 1}{4 - (-1)} = \frac{0 - 1}{4 + 1} = \frac{-1}{5} = -\frac{1}{5} \][/tex]

So, the slope [tex]\(m_1\)[/tex] between [tex]\((-1, 1)\)[/tex] and [tex]\((4, 0)\)[/tex] is [tex]\(-\frac{1}{5}\)[/tex].

### Step 2: Calculate the slope between the next two points [tex]\((4, 0)\)[/tex] and [tex]\((24, -4)\)[/tex]

Using the same slope formula for the points [tex]\((4, 0)\)[/tex] and [tex]\((24, -4)\)[/tex]:
[tex]\[ m = \frac{-4 - 0}{24 - 4} = \frac{-4}{20} = -\frac{1}{5} \][/tex]

So, the slope [tex]\(m_2\)[/tex] between [tex]\((4, 0)\)[/tex] and [tex]\((24, -4)\)[/tex] is also [tex]\(-\frac{1}{5}\)[/tex].

### Step 3: Check if the points are collinear

Since both slopes [tex]\(m_1\)[/tex] and [tex]\(m_2\)[/tex] are equal ([tex]\(-\frac{1}{5}\)[/tex]), the points are collinear. This means they lie on the same straight line.

### Step 4: Determine the equation of the line

Since the points are collinear and the slope of the line is [tex]\(-\frac{1}{5}\)[/tex], we can use the point-slope form of the line equation:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]

Using the point [tex]\((-1, 1)\)[/tex] and the slope [tex]\(m = -\frac{1}{5}\)[/tex]:
[tex]\[ y - 1 = -\frac{1}{5}(x - (-1)) \][/tex]
[tex]\[ y - 1 = -\frac{1}{5}(x + 1) \][/tex]
[tex]\[ y - 1 = -\frac{1}{5}x - \frac{1}{5} \][/tex]

Solving for [tex]\(y\)[/tex]:
[tex]\[ y = -\frac{1}{5}x - \frac{1}{5} + 1 \][/tex]
[tex]\[ y = -\frac{1}{5}x + \frac{4}{5} \][/tex]

Thus, the equation of the line is:
[tex]\[ y = -\frac{1}{5}x + \frac{4}{5} \][/tex]

### Conclusion

Among the given options, the equation that matches this derivation is:
[tex]\[ y = -\frac{1}{5} x + \frac{4}{5} \][/tex]

Therefore, the correct equation of the line through the points [tex]\((-1, 1)\)[/tex], [tex]\((4, 0)\)[/tex], and [tex]\((24, -4)\)[/tex] is [tex]\(y = -\frac{1}{5} x + \frac{4}{5}\)[/tex], corresponding to option 2.