what role multiplicative inverses have on the existence of solutions for a system of linear equations
The correct answer and explanation is:
The concept of multiplicative inverses plays a critical role in determining the existence of solutions in a system of linear equations, particularly in relation to matrix representation and matrix operations. When a system of linear equations is expressed in matrix form as Ax = b, where A is a matrix representing the coefficients of the system, x is the vector of variables, and b is the constant vector, the multiplicative inverse of A can determine whether the system has a unique solution.
For a matrix A to have a multiplicative inverse, it must be invertible, meaning that A must be a square matrix and its determinant must be non-zero. The determinant of A is a scalar value that reflects the matrix’s ability to perform a one-to-one mapping. If the determinant is zero, the matrix is singular, meaning it does not have an inverse, and the system may either have no solution or infinitely many solutions. If the determinant is non-zero, the matrix is non-singular, meaning it has a multiplicative inverse, and the system has a unique solution.
When A is invertible, the system of equations can be solved using the formula x = A^(-1) * b, where A^(-1) is the multiplicative inverse of A. The existence of a multiplicative inverse allows for a direct computation of the solution vector x, ensuring that there is exactly one solution to the system.
On the other hand, if A is not invertible (i.e., if its determinant is zero), the system cannot be solved using this method. In such cases, the system may still have solutions, but they will not be unique. Alternatively, the system may have no solution, depending on the relationship between A and b.
In summary, the multiplicative inverse of the coefficient matrix is crucial in ensuring that a system of linear equations has a unique solution, as it directly affects the matrix’s invertibility and the solvability of the system.