What is one ordered pair that will work for both systems of inequalities?
y>-2x+3
y<4x-1
y>-2x+3
y<4x-1
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-2x+3 < y < 4x-1
-6x < -4
x > 2/3
Pick an x > 2/3. For example x = 1
-2+3 < y < 4-1
1 < y < 3
Pick a y between 1 and 3. For example y = 2
The ordered pair (x,y) = (1,2) satisfies both inequalities.
Check:
2 > -2*1+3
2 > 1 : true statement
2 < 4-1
2 < 3 : true statement
-6x < -4
x > 2/3
Pick an x > 2/3. For example x = 1
-2+3 < y < 4-1
1 < y < 3
Pick a y between 1 and 3. For example y = 2
The ordered pair (x,y) = (1,2) satisfies both inequalities.
Check:
2 > -2*1+3
2 > 1 : true statement
2 < 4-1
2 < 3 : true statement
-
y > - 2x + 3 graphs as a straight line with a negative slope, so y is everything above the line.
y < 4x - 1 graphs as a straight line with a positive slope, so y is everything below the line.
The intersection is given by
- 2x + 3 = 4x - 1
- 2x - 4x = - 1 - 3
- 6x = - 4
x = - 4 / - 6
x = 2/3
and
y = - 2(2/3) + 3
y = - 4/3 + 9/3
y = 5/3
Intersection (2/3, 5/3)
The domain, then, would be everything between the two lines beginning at (2/3, 5/3) excluding any values that are on the lines.
...
y < 4x - 1 graphs as a straight line with a positive slope, so y is everything below the line.
The intersection is given by
- 2x + 3 = 4x - 1
- 2x - 4x = - 1 - 3
- 6x = - 4
x = - 4 / - 6
x = 2/3
and
y = - 2(2/3) + 3
y = - 4/3 + 9/3
y = 5/3
Intersection (2/3, 5/3)
The domain, then, would be everything between the two lines beginning at (2/3, 5/3) excluding any values that are on the lines.
...
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(7,1)
If you graph the lines on your graphing calculator, you see that anything above the line Y=-2x+3 is fair game, as long as its below y=4x-1
If you graph the lines on your graphing calculator, you see that anything above the line Y=-2x+3 is fair game, as long as its below y=4x-1
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x = 10, y = 10