How do you find the slope and intercept to graph 3x+4y=12?

1 Answer
Mar 28, 2018

y=34x3

The slope is 34

The y-intercept is at (0,3)

Explanation:

The best way to find the slope and the y-intercept of the given line is to re-write the equation in the slope-intercept form.
That way, you can read the slope and the y-intercept directly from the equation.

The slope-intercept form of an equation is
y=mx+b
where m is the slope and b is the y-intercept.

Rewrite the equation in the slope-intercept form

Given 3x+4y=12    Solve for y

1) Subtract 3x from both sides to isolate the 4y term
After you subtract, you will get this:
4y=3x12

2) Divide all the terms on both sides by 4 to isolate y
y=34x3

This equation tells you that the slope is 34, and that the y-intercept us at (0,3)

You can click here to see the graph of this line
https://www.google.com/search?source=hp&ei=eOO7WuTpMYKL5wK8qY6ADw&q=y+%3D+-%283%2F4%29x+-+3&oq=y+%3D+-%283%2F4%29x+-+3&gs_l=psy-ab.12...1454.13188.0.16952.16.15.0.0.0.0.156.1364.9j5.14.0....0...1.1.64.psy-ab..2.4.478.0..0j0i131k1.0.sih2wBD0tnI

Or you can use the Mathway graphing tool to see this line
https://www.mathway.com/PreAlgebra?problem=eT0oMykvKDQpeC0z
(Change the web site's slope of 34 into your wanted slope of 34 )