Find a linear inequality with the following solution set. Each grid line represents one unit.
(Give your answer in "standard form"ax+by+c>0,or,ax+by+c≥0 where a, b, and c are integers with no common factor greater than 1.)
+9488 Start by finding the equation of the red line.
The red line passes through the points (1, -2) and (3, 1)
slope of red line = riserun = 1−−23−1 = 32
Using the point (1, -2) and the slope 32 , the equation of the red line in point-slope form is:
y + 2 = 32(x - 1)
Multiply both sides of the equation by 2 .
2(y + 2) = 3(x - 1)
Distribute.
2y + 4 = 3x - 3
Subtract 3x from both sides and add 3 to both sides.
-3x + 2y + 7 = 0
And the red line is dotted, so it is not included in the inequality. So the liner inequality of the graph is either
-3x + 2y + 7 > 0 or -3x + 2y + 7 < 0
To determine which one, pick a point which we know should make the inequality true and test that point.
We know that the point (0, 0) should make the inequality true.
Is it true that -3(0) + 2(0) + 7 > 0 ? Yes, it is true that 7 > 0 .
So the linear inequality of the graph is -3x + 2y + 7 > 0
+9488 Start by finding the equation of the red line.
The red line passes through the points (1, -2) and (3, 1)
slope of red line = riserun = 1−−23−1 = 32
Using the point (1, -2) and the slope 32 , the equation of the red line in point-slope form is:
y + 2 = 32(x - 1)
Multiply both sides of the equation by 2 .
2(y + 2) = 3(x - 1)
Distribute.
2y + 4 = 3x - 3
Subtract 3x from both sides and add 3 to both sides.
-3x + 2y + 7 = 0
And the red line is dotted, so it is not included in the inequality. So the liner inequality of the graph is either
-3x + 2y + 7 > 0 or -3x + 2y + 7 < 0
To determine which one, pick a point which we know should make the inequality true and test that point.
We know that the point (0, 0) should make the inequality true.
Is it true that -3(0) + 2(0) + 7 > 0 ? Yes, it is true that 7 > 0 .
So the linear inequality of the graph is -3x + 2y + 7 > 0
