How do you graph the system of linear inequalities 2x+y<62x+y<6 and y> -2y>2?

Redirected from "Can mixtures be separated by chromatography?"
1 Answer
Apr 22, 2015

2x+y<62x+y<6 and y > -2y>2
First consider the related linear equations:
2x+y=6 rarr y = -2x+62x+y=6y=2x+6
and
y = -2y=2

y = -2x+6y=2x+6
is a line with y-intercept at (0,6)(0,6) and a slope of (-2)(2) (which means that for every unit increase in xx, yy decreases by 22)

y=-2y=2
is a horizontal line through the point (0,-2)(0,2)

It is fairly simple to plot these lines;
then we just need to determine which sides of these lines need to be combined for the given inequalities
Since
y>-2y2
the points of the Range must be above the horizontal line

Since
2x+y<62x+y<6
the points of the Range must be below the line for 2x+y=62x+y=6 (since if y_1y1 is in the Range and y_2<y_1y2<y1 then y_2y2 must also be in the Range).
enter image source here