What is the slope and y-intercept of the line #9x+3y=12#?

1 Answer
Jun 6, 2016

Answer:

The slope is #-3# and the y-intercept is #4#.

Explanation:

It helps if you put your equation into the standard linear form of #y=mx+b#. In this form, #m# is always the slope, and #b# is always the y-intercept.

To get it into standard form, you need to isolate #y#. To do this, I can first move the #9x# by subtracting it from each side of the equation, giving me:

#3y = -9x + 12#

Then, I would divide each side by 3, to isolate the #y#. The distributive property requires that both #-9y# and #12# be divided by 3 as well. This gives me:

#y = -3x +4#

Now I have my equation in standard form, and can see that the slope is #-3# and the y-intercept is #4#. That can be reflected by graphing the line as well: graph{-3x +4 [-4.834, 5.166, -0.54, 4.46]}