How do you graph the linear inequality -2x - 5y<10?

1 Answer
Mar 13, 2018

See a solution process below:

Explanation:

First, solve for two points as an equation instead of an inequality to find the boundary line for the inequality.

For: x = 0

(-2 * 0) - 5y = 10

0 - 5y = 10

-5y = 10

(-5y)/color(red)(-5) = 10/color(red)(-5)

y = -2 or (0, -2)

For: y = 0

-2x - (5 * 0) = 10

-2x - 0 = 10

-2x = 10

(-2x)/color(red)(-2) = 10/color(red)(-2)

x = -5 or (-5, 0)

We can now graph the two points on the coordinate plane and draw a line through the points to mark the boundary of the inequality.

graph{(x^2+(y+2)^2-0.05)((x+5)^2+y^2-0.05)(-2x-5y-10)=0 [-10, 10, -5, 5]}

Now, we can shade the rightside of the line.

The boundary line will need to be changed to a dashed line because the inequality operator does not contain an "or equal to" clause.

graph{(-2x-5y-10) < 0 [-10, 10, -5, 5]}