Graph of the System of Inequalities, 3

Category: Analytic Geometry

"Published in Vacaville, California, USA"

Graph the solution of the system of inequalities and find the coordinates of all vertices for

x ≥ 0

y ≥ 0

3x + 5y ≤ 15

3x + 2y ≤ 9

Solution:

For x ≥ 0, the given line is a vertical line in which all points along the line are included in the solution. However, all points at the right of the given line are included in the solution.

For y ≥ 0, the given line is a horizontal line in which all points along the line are included in the solution. However, all points above of the given line are included in the solution.

For 3x + 5y ≤ 15, we need to rewrite the given equation into slope-intercept form as follows

Since the sign of inequality is less than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≤ 15 which is correct and that point is included in the solution.  

For 3x + 2y ≤ 9, we need to rewrite the given equation into slope-intercept form as follows

Since the sign of inequality is less than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≤ 9 which is correct and that point is included in the solution. Therefore, the graph of a set of linear inequalities is

Photo by Math Principles in Everyday Life

The vertices of the graph are (0, 0), (0, 3), (1 2/3, 2) and (3, 0) that are located at the intersection of the four shaded regions bounded by four lines.
 

Graph of the System of Inequalities, 2

Category: Analytic Geometry

"Published in Vacaville, California, USA"

Graph the solution of the system of inequalities and find the coordinates of all vertices for

x + 2y ≤ 14

3x - y ≥ 0

x - y ≥ 2

Solution:

For x + 2y ≤ 14, we need to rewrite the given equation into slope-intercept form as follows 

     

Since the sign of inequality is less than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≤ 14 which is correct and that point is included in the solution.  

For 3x - y ≥ 0, we need to rewrite the given equation into slope-intercept form as follows

If you divide both sides of the equation by a negative number, then the sign of inequality will be reversed. Since the sign of inequality is greater than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≥ 0 which is correct and that point is included in the solution.  

For x - y ≥ 2, we need to rewrite the given equation into slope-intercept form as follows  

If you divide both sides of the equation by a negative number, then the sign of inequality will be reversed. Since the sign of inequality is greater than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≥ 2 which is not correct and that point is not included in the solution. Therefore, the graph of a set of linear inequalities is

Photo by Math Principles in Everyday Life

The vertices of the graph are (-1, -3) and (6, 4) that are located at the intersection of the three shaded regions bounded by three lines.

Graph of the System of Inequalities

Category: Analytic Geometry

"Published in Vacaville, California, USA"

Graph the solution of the system of inequalities and find the coordinates of all vertices for

a. x + y ≤ 4
          y ≥ x

b. 2x + 3y > 12
     3x - y < 21

Solution:

a. For x + y ≤ 4, we need to rewrite the given equation into slope-intercept form as follows

Since the sign of inequality is less than or equal to, then all points along the line are included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 ≤ 4 which is correct and that point is included in the solution.  

For y ≥ x, the given equation is already written in slope-intercept form. If x = 0 and y = 0, then the given equation reduces to 0 ≥ 0 which is correct and that point is included in the solution. Therefore, the graph of a pair of linear inequalities is

Photo by Math Principles in Everyday Life

The vertex of the graph is (2, 2) which is the intersection of two lines. It is also included in the solution.

b. For 2x + 3y > 12, we need to rewrite the given equation into slope-intercept form as follows

Since the sign of inequality is greater than, then all points along the line are not included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 > 12 which is not correct and that point is not included in the solution.  

For 3x - y < 21, we need to rewrite the given equation into slope-intercept form as follows

If you divide both sides of the equation by a negative number, then the sign of inequality will be reversed. Since the sign of inequality is less than, then all points along the line are not included in the solution. If x = 0 and y = 0, then the given equation reduces to 0 < 21 which is correct and that point is  included in the solution. Therefore, the graph of a pair of linear inequalities is

Photo by Math Principles in Everyday Life

The vertex of the graph which is the intersection of two lines  is not included in the solution.