How do you find the slope and intercept of # -x + 3y = -12#?

1 Answer
May 25, 2016

Slope: #1/3#

Explanation:

Two ways to determine the slope for a question like this one.

Method 1: convert the given equation into slope-intercept form.
An equation in the form:
#color(white)("XXX")y=color(green)(m)x+color(blue)(b)#
is in "slope-intercept form" with a slope of #color(green)(m)# and a y-intercept of #color(blue)(b)#

Given
#color(white)("XXX")-x+3y=-12#

#color(white)("XXX")3y=x-12#

#color(white)("XXX")y=color(green)(1/3)x+color(blue)(""(-6))#

Method 2: less common for some reason
Given an equation in the form
#color(white)("XXX")Ax+By=C#
the slope is #color(red)(-A/B)#

For the given example
#color(white)("XXX")A=(-1)color(white)("XX")andcolor(white)("XX")B=3#