JEE Main 2020
Matrices & Determinants
Matrices and Determinants
Medium
Question
If the system of linear equations, x + y + z = 6 x + 2y + 3z = 10 3x + 2y + z = has more than two solutions, then - 2 is equal to ______.
Answer: 2
Solution
Key Concept: Conditions for Solutions of a System of Linear Equations
For a system of linear equations in three variables, represented in matrix form as , where is the coefficient matrix, is the variable matrix, and is the constant matrix, we can use Cramer's Rule to determine the nature of its solutions.
Let be the determinant of the coefficient matrix. Let be the determinants obtained by replacing the 1st, 2nd, and 3rd columns of respectively with the constant terms from matrix .
There are three possibilities for the solutions:
- Unique Solution: If