Matrices with variables need to be resolved using the RREF command on the calculator.
The following system of equations will be used for the example in this document:
Ax + 5y = 10
5x + y = B
Normally, a system of linear equations is solved by using the "Solve Linear System" option under the numeric solver. However, attempting to enter the variable A for the first coefficient will cause a "Bad Argument Type" error to be displayed. This is because the linear system solver is designed to solve problems numerically, not symbolically. The solution to this problem is to use the RREF command instead of the linear solver. RREF stands for "reduced row echelon form," which requires the first nonzero entry in each row to be a one and also the only nonzero entry in its column.