SOLUTION: I need some help with these graph problems. I would appreciate some help with solving and graphing these systems. Thank you. Solve the system by graphing. x+y=4 -x+y=2 S

Algebra ->  Graphs -> SOLUTION: I need some help with these graph problems. I would appreciate some help with solving and graphing these systems. Thank you. Solve the system by graphing. x+y=4 -x+y=2 S      Log On


   



Question 86136: I need some help with these graph problems. I would appreciate some help with solving and graphing these systems. Thank you.
Solve the system by graphing.
x+y=4
-x+y=2

Solve the following systym of linear inequalities by graphing.
3x+4y<12
x+3y<6
x>0
y>0 (under each of the greater and lesser signs is a line)

Solve the following system of linear inequalities by graphing.
x+2y<3
2x-3y<6
Solve the following system of linear inequalities by graphing
x-2y>4
x<4
Thank you so much for taking your time to help me out. thanks alot.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Solve the System of Equations by Graphing



Start with the given system of equations:


1x%2By=4

-x%2By=2





In order to graph these equations, we need to solve for y for each equation.




So let's solve for y on the first equation


1x%2By=4 Start with the given equation



1y=4-x Subtract +x from both sides



1y=-x%2B4 Rearrange the equation



y=%28-x%2B4%29%2F%281%29 Divide both sides by 1



y=%28-1%2F1%29x%2B%284%29%2F%281%29 Break up the fraction



y=-x%2B4 Reduce



Now lets graph y=-x%2B4 (note: if you need help with graphing, check out this solver)



+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-x%2B4%29+ Graph of y=-x%2B4




So let's solve for y on the second equation


-x%2By=2 Start with the given equation



1y=2%2Bx Add +x to both sides



1y=%2Bx%2B2 Rearrange the equation



y=%28%2Bx%2B2%29%2F%281%29 Divide both sides by 1



y=%28%2B1%2F1%29x%2B%282%29%2F%281%29 Break up the fraction



y=x%2B2 Reduce





Now lets add the graph of y=x%2B2 to our first plot to get:


+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-x%2B4%2Cx%2B2%29+ Graph of y=-x%2B4(red) and y=x%2B2(green)


From the graph, we can see that the two lines intersect at the point (1,3) (note: you might have to adjust the window to see the intersection)




--------------------------------------------------------------------------

Start with the given system of inequalities
3x%2B4y%3C=12

x%2B3y%3C=6

x%3E=0

y%3E=0



In order to graph this system of inequalities, we need to graph each inequality one at a time.

So lets graph the first inequality

In order to graph 3x%2B4y%3C=12 we need to graph the equation 3x%2B4y=12 (just replace the inequality sign with an equal sign). So lets graph the line 3x%2B4y=12 (note: if you need help with graphing, check out this solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%2812-3%2Ax%29%2F4%29 graph of 3x%2B4y=12
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality 3x%2B4y%3C=12
3%280%29%2B4%280%29%3C=12 Plug in x=0, y=0

0%3C=12 Simplify


Since this inequality is true, we shade the entire region containing (0,0)



Here is the graph of 3x%2B4y%3C=12 with the graph of the line(3x%2B4y=12) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)




Now lets graph the second inequality

In order to graph x%2B3y%3C=6 we need to graph the equation x%2B3y=6 (just replace the inequality sign with an equal sign). So lets graph the line x%2B3y=6 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%286-1%2Ax%29%2F3%29 graph of x%2B3y=6
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality x%2B3y%3C=6
%280%29%2B3%280%29%3C=6 Plug in x=0, y=0

0%3C=6 Simplify


Since this inequality is true, we shade the entire region containing (0,0)



Here is the graph of x%2B3y%3C=6 with the graph of the line(x%2B3y=6) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)




Now lets graph the third inequality

In order to graph x%3E=0 we need to graph the equation x=0 (just replace the inequality sign with an equal sign). So lets graph the line x=0 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C1000%28x-100%2F1000%29%29 graph of x=0 (it is the same line as the axis)
Now lets pick a test point, say (1,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality x%3E=0
%281%29%3E=0 Plug in x=1

1%3E=0 Simplify


Since this inequality is true, we shade the entire region that contain (1,0)



Here is the graph of x%3E=0 with the graph of the line(x=0) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)




Now lets graph the fourth inequality

In order to graph y%3E=0 we need to graph the equation y=0 (just replace the inequality sign with an equal sign). So lets graph the line y=0 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%28100-1%2Ax%29%2F1000%29 graph of y=0 ((it is the same line as the axis)
Now lets pick a test point, say (0,1) (any point will work, but this point is the easiest to work with), and evaluate the inequality y%3E=0
%281%29%3E=0 Plug in y=1

1%3E=0 Simplify


Since this inequality is true, we shade the entire region that contain (0,1)



Here is the graph of y%3E=0 with the graph of the line(y=0) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)
So we essentially have these 4 regions
Region #1 which is the graph of 3x%2B4y%3C=12
Region #2 which is the graph of x%2B3y%3C=6
Region #3 which is the graph of x%3E=0
Region #4 which is the graph of y%3E=0


So these regions overlap to produce this region. It's a little hard to see, but after evenly shading each region, the intersecting region will be the most shaded in.

Here is a cleaner look at the intersection of regions

Here is the intersection of the 4 regions represented by the dots

--------------------------------------------------------------------------

Start with the given system of inequalities
x%2B2y%3C=3

2x-3y%3C=6



In order to graph this system of inequalities, we need to graph each inequality one at a time.

So lets graph the first inequality

In order to graph x%2B2y%3C=3 we need to graph the equation x%2B2y=3 (just replace the inequality sign with an equal sign). So lets graph the line x%2B2y=3 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%283-1%2Ax%29%2F2%29 graph of x%2B2y=3
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality x%2B2y%3C=3
%280%29%2B2%280%29%3C=3 Plug in x=0, y=0

0%3C=3 Simplify


Since this inequality is true, we shade the entire region containing (0,0)



Here is the graph of x%2B2y%3C=3 with the graph of the line(x%2B2y=3) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)




Now lets graph the second inequality

In order to graph 2x-3y%3C=6 we need to graph the equation 2x-3y=6 (just replace the inequality sign with an equal sign). So lets graph the line 2x-3y=6 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%286-2%2Ax%29%2F-3%29 graph of 2x-3y=6
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality 2x-3y%3C=6
2%280%29-3%280%29%3C=6 Plug in x=0, y=0

0%3C=6 Simplify


Since this inequality is true, we shade the entire region containing (0,0)



Here is the graph of 2x-3y%3C=6 with the graph of the line(2x-3y=6) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)
So we essentially have these 2 regions
Region #1 which is the graph of x%2B2y%3C=3
Region #2 which is the graph of 2x-3y%3C=6


So these regions overlap to produce this region. It's a little hard to see, but after evenly shading each region, the intersecting region will be the most shaded in.

Here is a cleaner look at the intersection of regions

Here is the intersection of the 2 regions represented by the dots

--------------------------------------------------------------------------

Start with the given system of inequalities
x-2y%3E=4

x%3C=4



In order to graph this system of inequalities, we need to graph each inequality one at a time.

So lets graph the first inequality

In order to graph x-2y%3E=4 we need to graph the equation x-2y=4 (just replace the inequality sign with an equal sign). So lets graph the line x-2y=4 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C%284-1%2Ax%29%2F-2%29 graph of x-2y=4
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality x-2y%3E=4
%280%29-2%280%29%3E=4 Plug in x=0, y=0

0%3E=4 Simplify


Since this inequality is not true, we shade the entire region that doesn't contain (0,0)



Here is the graph of x-2y%3E=4 with the graph of the line(x-2y=4) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)




Now lets graph the second inequality

In order to graph x%3C=4 we need to graph the equation x=4 (just replace the inequality sign with an equal sign). So lets graph the line x=4 (note: if you need help with graphing, check out this
solver)
graph%28+400%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C1000%28x-4000%2F1000%29%29 graph of x=4
Now lets pick a test point, say (0,0) (any point will work, but this point is the easiest to work with), and evaluate the inequality x%3C=4
%280%29%3C=4 Plug in x=0, y=0

0%3C=4 Simplify


Since this inequality is true, we shade the entire region containing (0,0)



Here is the graph of x%3C=4 with the graph of the line(x=4) in red and the shaded region in green
(note: In this case, the red line is a solid line. This means the boundaries are included in the region.)
So we essentially have these 2 regions
Region #1 which is the graph of x-2y%3E=4
Region #2 which is the graph of x%3C=4


So these regions overlap to produce this region. It's a little hard to see, but after evenly shading each region, the intersecting region will be the most shaded in.

Here is a cleaner look at the intersection of regions

Here is the intersection of the 2 regions represented by the dots