How do you graph #2x+y=-2# using intercepts?

2 Answers
May 29, 2017

Answer:

Find two vaules for #x# and #y# that solve the equation, sketch them on a graph, and draw a line going through both points.

Explanation:

The easiest method is by finding two coordinates.
Find two vaules for #x# and #y# that solve the equation, sketch them on a graph, and draw a line going through both points.

To find a co-ordinate, we must pick any #x#, or any #y#.

Let's pick #x=2#.

Then substitute into the equation:
#2x+y=-2#
#2(2)+y=-2#
#4+y=-2#
#y=-2-4#
#y=-6#

So the first coordinate is #[2,-6]#

Then repeat picking a different #x# or #y# value.
Assume #y=7#
#2x+y=7#
#2x+7=7#
#2x=0#
#x=0#
Second coordinate: #[0,7]#

Then simply sketch a line between #[2,-6]# and #[0,7]#
graph{2x+y=-2 [-17.81, 17.81, -8.9, 8.91]}

May 29, 2017

Answer:

#"see explanation"#

Explanation:

#color(blue)"finding the intercepts"#

#• " let x = 0, in the equation for y-intercept"#

#• " let y = 0, in the equation for x-intercept"#

#x=0to0+y=-2toy=-2larrcolor(red)" y-intercept"#

#y=0to2x+0=-2tox=-1larrcolor(red)" x-intercept"#

#"plot these 2 points and draw a straight line through them"#
graph{-2x-2 [-10, 10, -5, 5]}