Which of the following linear equations passes through the points [tex]\((-1, 5)\)[/tex] and [tex]\((1, -5)\)[/tex]?

[tex]\[
\begin{array}{l}
A. \ y = -5x \\
B. \ y = 5x + 10 \\
C. \ y = -2x + 3
\end{array}
\][/tex]

D. None of these choices are correct.



Answer :

Let's find the equation of the line that passes through the points [tex]\((-1, 5)\)[/tex] and [tex]\((1, -5)\)[/tex].

1. Calculate the slope (m) of the line:

The formula for the slope between two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is given by:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Plugging in the points [tex]\((-1, 5)\)[/tex] and [tex]\((1, -5)\)[/tex]:
[tex]\[ m = \frac{-5 - 5}{1 - (-1)} = \frac{-10}{2} = -5 \][/tex]

2. Find the y-intercept (b) of the line:

Using the point-slope form of the equation of a line:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]
We can rearrange this into the slope-intercept form:
[tex]\[ y = mx + b \][/tex]

Let's use the point [tex]\((-1, 5)\)[/tex]:
[tex]\[ 5 = (-5)(-1) + b \][/tex]
Simplify and solve for [tex]\(b\)[/tex]:
[tex]\[ 5 = 5 + b \implies b = 0 \][/tex]

Therefore, the equation of the line in slope-intercept form is:
[tex]\[ y = -5x + 0 \quad \text{or simply} \quad y = -5x \][/tex]

3. Compare with the given equations:

The given options for the equations are:
[tex]\[ \begin{array}{l} y = -5x \\ y = 5x + 10 \\ y = -2x + 3 \end{array} \][/tex]

The equation that matches our derived equation [tex]\(y = -5x\)[/tex] is the first one [tex]\(y = -5x\)[/tex].

Therefore, the correct linear equation that passes through the points [tex]\((-1, 5)\)[/tex] and [tex]\((1, -5)\)[/tex] is:

[tex]\[ y = -5x \][/tex]