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For the following systems, determine

(1) the augmented matrix,
(2) an echelon form of the matrix,
(3) the reduced echelon form of the matrix,
(4) whether the system is consistent,
(5) the set of solutions (in parametric form),
(6) how many solutions the system has,
(7) the geometric interpretation of the set of solutions.

System A:
x2 = 3
x1 + 2x2 = 4
System B:
x1 + x2 = 3
2x1 + 2x2 = 6

User Germ
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1 Answer

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(1) Augmented Matrix:

For System A:

| 1 2 3 |
| 1 2 4 |

For System B:

| 1 1 3 |
| 2 2 6 |

(2) Echelon Form:

For System A:

| 1 2 3 |
| 0 0 2 |

For System B:

| 1 1 3 |
| 0 0 0 |

(3) Reduced Echelon Form:

For System A:

| 1 2 3 |
| 0 0 2 |

For System B:

| 1 1 3 |
| 0 0 0 |

(4) Consistency:

A system of linear equations is consistent if it has at least one solution. If a system of linear equations is in reduced echelon form and has a row of zeros on the right-hand side, then it is inconsistent (no solutions). If the right-hand side is not all zeros, then it is consistent (has at least one solution).

For System A: consistent (has at least one solution)
For System B: inconsistent (no solutions)

(5) Set of Solutions (in parametric form):

For System A:
x1 = t
x2 = 3
t is a free variable and can take any value, so the set of solutions is:
x1 = t, x2 = 3

For System B:
The system is inconsistent, so there is no set of solutions.

(6) Number of Solutions:

For System A: infinitely many solutions
For System B: no solutions

(7) Geometric Interpretation:

The geometric interpretation of the set of solutions is a line (for System A) or the empty set (for System B) in two-dimensional space. The variables x1 and x2 can be thought of as coordinates in a two-dimensional plane, and each equation in the system represents a constraint on the values that x1 and x2 can take. In System A, the set of solutions represents all the points in the two-dimensional plane that satisfy both constraints, which is a line. In System B, the constraints are incompatible, so there is no point in the two-dimensional plane that satisfies both, which is represented by the empty set.
User PiyushMishra
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