# How do you write the equation of line passes through (-2,-2), and is perpendicular to y= -1/3x + 9?

##### 1 Answer

Oct 31, 2017

#### Explanation:

#"given the slope of a line m then the slope of a line"#

#"perpendicular to it is"#

#•color(white)(x)m_(color(red)"perpendicular")=-1/m#

#"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"#

#y=-1/3x+9" is in this form with "m=-1/3#

#rArrm_(color(red)"perpendicular")=-1/(-1/3)=3#

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

#"to find b substitute "(-2,-2)" into the partial equation"#

#-2=-6+brArrb=4#

#rArry=3x+4larrcolor(red)"equation of perpendicular line"#