i'm having some trouble with linear system in hp 50g. I write the matrix with the coeficients in "a" and the results in "b" but when I click "solve" the display show the message "bad argument type" . I've checked the values and they are wright but the calculator insists in this error, even with the most simple linear system.
Bad Argument Type means one of the two matrices in not valid for the desired function. If you're sure both your matrices are valid then you can try executing CASCFG command, which reconfigures all the algebraic parameters and try solving again. Sometimes we install programs that mess up our configuration and leave the calculator "acting weird".
Also you can use the Matrix Writer to input both matrices and solve the system on the stack: Create a COE matrix with the coefficients and another, let's say B, with the independent terms. The folloeing procedure is to be executed in RPN mode:
COE 1/X B * this leaves the solution on the stack. 1/X is the key right above 9.