Question

What is the equation in point-slope form of a line that passes through the points (−4, −1) and (5, 7) ? y+1=87(x+4) y+4=98(x+1) y−1=89(x−4) y+1=89(x+4)

Answer 1

I think its 4+(-98=y)

Answer 2

ANSWER

The equation in point-slope form is
$y + 1 = \frac{8}{9} (x + 4).$


EXPLANATION

The equation of a line in point slope form is given by,


$y-y_1=m(x-x_1)$

where
$m$
is the slope and
$(x_1,y_1)$
is any given point on the line.


Let us now find the slope using the point,

$(-4,-1) \: and \: (5,7)$


We apply the slope formula,

$m=\frac{y_2-y_1}{x_2-x_1}$

This implies that,

$m = \frac{7 - - 1}{5 - - 4}$


$m = \frac{7 + 1}{5 + 4}$


$m = \frac{8}{9}$


The equation is now given by,

$y - - 1 = \frac{8}{9} (x - - 4)$

Or

$y + 1 = \frac{8}{9} (x + 4)$


The correct answer is D