Write the equations of the following lines.

a. A line with slope [tex]$-\frac{1}{2}$[/tex] through [tex]$(5, -2)$[/tex].

b. A line through the points [tex][tex]$(1, 4)$[/tex][/tex] and [tex]$(3, 0)$[/tex].



Answer :

Sure, let's solve each part step-by-step:

### Part (a)
We need to find the equation of a line with a slope of [tex]\(-\frac{1}{2}\)[/tex] that passes through the point [tex]\((5, -2)\)[/tex]. We will use the point-slope form of the equation of a line:

[tex]\[ y - y_1 = m(x - x_1) \][/tex]

where [tex]\(m\)[/tex] is the slope and [tex]\((x_1, y_1)\)[/tex] is a point on the line. Here, [tex]\(m = -\frac{1}{2}\)[/tex], [tex]\(x_1 = 5\)[/tex], and [tex]\(y_1 = -2\)[/tex].

Substituting these values into the formula, we get:

[tex]\[ y - (-2) = -\frac{1}{2}(x - 5) \][/tex]
[tex]\[ y + 2 = -\frac{1}{2}x + \frac{5}{2} \][/tex]

Now, solve for [tex]\(y\)[/tex] to get it into slope-intercept form [tex]\(y = mx + b\)[/tex]:

[tex]\[ y = -\frac{1}{2}x + \frac{5}{2} - 2 \][/tex]
[tex]\[ y = -\frac{1}{2}x + \frac{5}{2} - \frac{4}{2} \][/tex]
[tex]\[ y = -\frac{1}{2}x + \frac{1}{2} \][/tex]

So, the equation of the line is:

[tex]\[ y = -\frac{1}{2}x + \frac{1}{2} \][/tex]

### Part (b)
We need to find the equation of a line that passes through the points [tex]\((1, 4)\)[/tex] and [tex]\((3, 0)\)[/tex]. First, calculate the slope [tex]\(m\)[/tex] using the formula:

[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Taking [tex]\((x_1, y_1) = (1, 4)\)[/tex] and [tex]\((x_2, y_2) = (3, 0)\)[/tex]:

[tex]\[ m = \frac{0 - 4}{3 - 1} \][/tex]
[tex]\[ m = \frac{-4}{2} \][/tex]
[tex]\[ m = -2 \][/tex]

Next, use the point-slope form of the equation of a line with the slope [tex]\(m = -2\)[/tex] and one of the given points, say [tex]\((1, 4)\)[/tex]:

[tex]\[ y - y_1 = m(x - x_1) \][/tex]
[tex]\[ y - 4 = -2(x - 1) \][/tex]

Solve for [tex]\(y\)[/tex] to get it into slope-intercept form [tex]\(y = mx + b\)[/tex]:

[tex]\[ y - 4 = -2x + 2 \][/tex]
[tex]\[ y = -2x + 2 + 4 \][/tex]
[tex]\[ y = -2x + 6 \][/tex]

So, the equation of the line is:

[tex]\[ y = -2x + 6 \][/tex]

### Summary
The equations of the lines are:
a. [tex]\( y = -\frac{1}{2}x + \frac{1}{2} \)[/tex]
b. [tex]\( y = -2x + 6 \)[/tex]