Inconsistent Equations: A system of equations that has no solutions. .
Inconsistent inequalities:A system of inequalities that has no solutions.
Inconsistent equations: The system of equations given below is inconsistent.
4x - 5y = 7
8x - 10y = 7
Inconsistent inequalities: The system of inequalities given below is inconsistent.
x - y ≤ 0
x - y ≥ 7
Choices:
A. inconsistent
B. consistent and independent
C. consistent and dependent
D. consistent
Correct Answer: A
Step 1: 0.5x - 0.3y = 1.2 [Equation 1.]
Step 2: 1.5x - 0.9y = 2.1 [Equation 2.]
Step 3:
[Rearrange equation 1 in slope-intercept form.]
Step 4:
[Simplify.]
Step 5:
[Rearrange equation 2 in slope-intercept form.]
Step 6: 
Step 7: Graph the equations.

Step 8: The two lines are parallel.
Step 9: So, the linear system has no solution
Step 10:Therefore, the system is inconsistent
Q1: Which of the following systems is inconsistent?
Q: How can you tell if a system is inconsistent?
A: When solving, you arrive at a contradiction (e.g., 0 = 1). Graphically, the lines are parallel (for equations) or the regions don't overlap (for inequalities).
Q: Does an inconsistent system have any solutions?
A: No, an inconsistent system by definition has no solution.