Question

What's the equation of a line that passes through points (–1, –5) and (1, 3)? Question 20 options: y = –x + 4 y = 4x – 1 y = 1 4 x – 2 y = –2x

Answer 1

`(\stackrel{x_1}{-1}~,~\stackrel{y_1}{-5})\qquad (\stackrel{x_2}{1}~,~\stackrel{y_2}{3}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{3}-\stackrel{y1}{(-5)}}}{\underset{run} {\underset{x_2}{1}-\underset{x_1}{(-1)}}} \implies \cfrac{3 +5}{1 +1} \implies \cfrac{ 8 }{ 2 } \implies 4`

`\begin{array}ll \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{(-5)}=\stackrel{m}{ 4}(x-\stackrel{x_1}{(-1)}) \implies y +5 = 4 ( x +1) \\\\\\ y+5=4x+4\implies {\Large \begin{array}{llll} y=4x-1 \end{array}}`