Casio fx-991EX Quick Start Manual page 41

EQUATION/FUNC
To solve, press p and use the arrow keys (RE) to toggle
between solutions.
The solutions are shown in natural display format. For decimal
approximations, press n.
To change the values in the system of equations without
changing the type of equation or system, press C.
To change the type of equation or system size, press i and select from the on-screen menus.
The fx-991EX also solves inconsistent systems, both
independent and dependent. Enter the displayed inconsistent
and independent system
Press p to see the solution.
fx-991EX Quick Start Guide 41