Find an equation for the line, in the indicated form, with the given properties.
-Containing the points $( - 4 , - 1 )$ and $( 1,2 )$; slope-intercept form
A) $y = m x + \frac { 7 } { 5 }$
B) $y = - \frac { 3 } { 5 } x + \frac { 7 } { 5 }$
C) $y = \frac { 3 } { 5 } x + \frac { 7 } { 5 }$
D) $y + 1 = \frac { 3 } { 5 } ( x + 4 )$

Question

Quizplus · Accepted Answer

First, calculate the slope $m$ using the formula $m = \frac{y_2 - y_1}{x_2 - x_1}$, which gives $m = \frac{2 - (-1)}{1 - (-4)} = \frac{3}{5}$. Then, use the point-slope form $y - y_1 = m(x - x_1)$ with one of the points, say $(-4, -1)$, to get $y + 1 = \frac{3}{5}(x + 4)$. Simplify this to slope-intercept form $y = mx + b$ to find $b$. Substituting $m = \frac{3}{5}$ and the point $(-4, -1)$ into the equation gives $y = \frac{3}{5}x + \frac{7}{5}$, which matches choice C.

Find an Equation for the Line, in the Indicated Form (−4,−1)( - 4 , - 1 )(−4,−1)

Find an Equation for the Line, in the Indicated Form $( - 4 , - 1 )$