How do you write an equation of a line given (3,-1), m=-3?

2 Answers
Jun 7, 2018

#y=-3x+8#

Explanation:

We have
#y=-3x+n#
For #x=3,y=-1#
we get
#-1=-9+n#
so #n=8#

Jun 7, 2018

#y=-3x+8#

Explanation:

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

#•color(white)(x)y=mx+b#

#"where m is the slope and b the y-intercept"#

#"here "m=-3#

#y=-3x+blarrcolor(blue)"is the partial equation"#

#"to find b substitute "(3,-1)" into the partial equation"#

#-1=-9+brArrb=-1+9=8#

#y=-3x+8larrcolor(red)" is equation of line"#