How do you graph #4x-2y>20#?

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Answer 1 · 2018-03-20T18:40:49

See a solution process below:

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

For: #x = 0#

#(4 * 0) - 2y = 20#

#0 - 2y = 20#

#-2y = 20#

#(-2y)/color(red)(-2) = 20/color(red)(-)#

#y = -10# or #(0, -10)#

For: #y = 0#

#4x - (2 * 0) = 20#

#4x - 0 = 20#

#4x = 20#

#(4x)/color(red)(4) = 20/color(red)(4)#

#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+10)^2-0.25)((x-5)^2+y^2-0.25)(4x-2y-20)=0 [-30, 30, -15, 15]}

Now, we can shade the right side of the line.

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

graph{(4x-2y-20) > 0 [-30, 30, -15, 15]}