What is the equation of the line between $(3,-2)$ and $(5,1)$ ?

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Answer 1 · 2018-05-30T12:43:44

See a solution process below:

First, we need to determine the slope of the line. The formula for find the slope of a line is:

$m = (color(red)(y_2) - color(blue)(y_1))/(color(red)(x_2) - color(blue)(x_1))$

Where $(color(blue)(x_1), color(blue)(y_1))$ and $(color(red)(x_2), color(red)(y_2))$ are two points on the line.

Substituting the values from the points in the problem gives:

$m = (color(red)(1) - color(blue)(-2))/(color(red)(5) - color(blue)(3)) = (color(red)(1) + color(blue)(2))/(color(red)(5) - color(blue)(3)) = 3/2$

Now, we can use the point-slope formula to write an equation for the line. The point-slope form of a linear equation is:

$(y - color(blue)(y_1)) = color(red)(m)(x - color(blue)(x_1))$

Where $(color(blue)(x_1), color(blue)(y_1))$ is a point on the line and $color(red)(m)$ is the slope.

Substituting the slope we calculated above and the values from the first point in the problem gives:

$(y - color(blue)(-2)) = color(red)(3/2)(x - color(blue)(3))$

$(y + color(blue)(2)) = color(red)(3/2)(x - color(blue)(3))$

We can also substitute the slope we calculated above and the values from the second point in the problem giving:

$(y - color(blue)(1)) = color(red)(3/2)(x - color(blue)(5))$

Answer 2 · 2018-05-30T12:44:22

$y=3/2x-13/2$

$m=(y_2-y_1)/(x_2-x_1)=(1+2)/(5-3)=3/2$
So
$y=3/2x+n$
we have
$1=15/2+n$

so

$n=-13/2$

What is the equation of the line between (3,-2)(3,-2) and (5,1)(5,1)?