How do you write an equation of a line that passes through points (4,2), (-2,-4)?

1 Answer
Jim G.
May 16, 2017

#y=x-2#

Explanation:

#"the equation of a line in "color(blue)"slope-intercept form"# is.

#color(red)(bar(ul(|color(white)(2/2)color(black)(y=mx+b)color(white)(2/2)|)))#
where m represents the slope and b, the t-intercept.

#"to calculate m use the "color(blue)"gradient formula"#

#color(red)(bar(ul(|color(white)(2/2)color(black)(m=(y_2-y_1)/(x_2-x_1))color(white)(2/2)|)))#
where # (x_1,y_1),(x_2,y_2)" are 2 coordinate points"#

#"the 2 points are " (x_1,y_1)=(4,2),(x_2,y_2)=(-2,-4)#

#rArrm=(-4-2)/(-2-4)=(-6)/(-6)=1#

#rArry=x+blarr" partial equation"#

#"to find b, substitute either of the 2 given points into "#
#"the partial equation"#

#"using " (4,2)#

#2=4+brArrb=-2#

#rArry=x-2larrcolor(red)" in slope-intercept form"#
graph{x-2 [-10, 10, -5, 5]}

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