A dependent pair of linear equations is not always consistent. Here's why:
Dependent Equations: Two linear equations are called dependent if one can be obtained by multiplying or dividing the other by a constant. In other words, they represent the same line or the same plane, meaning they have infinitely many solutions.
Consistency: An equation system is consistent if it has at least one solution, and inconsistent if it has no solution. A dependent system of equations can be consistent, but not necessarily. The consistency depends on whether the two equations describe the same line or a contradictory situation.
Consistent Dependent Systems: If the two equations represent the same line, then the system is consistent and has infinitely many solutions.
Inconsistent Dependent Systems: However, if the equations are dependent but contradictory (e.g., two lines that are parallel but distinct), then the system would be inconsistent and have no solutions.
Example of a Consistent Dependent System:
Consider the system: x + y = 2 2x + 2y = 4
The second equation is just twice the first one, so these represent the same line. The system is consistent and has infinitely many solutions.
Example of an Inconsistent Dependent System:
Consider the system: x + y = 2 2x + 2y = 5
The second equation is a multiple of the first, but the constants on the right-hand side are different. This leads to a contradiction, so the system is inconsistent, meaning there are no solutions.
Conclusion:
A dependent system of linear equations is not always consistent. It can be consistent if the equations represent the same line or plane, but inconsistent if they represent contradictory conditions.