Casio fx-CG50 field manual for IB Math
Solving 3×3 equations
Solve a linear system with a unique solution using the calculator's dedicated solver (TI-84 PlySmlt2, Nspire linSolve, Casio EQUA).
Solve the system x+z=5, 2x−y+3z=12, and −x+4y+z=5.
From the MAIN MENU, open Equation. If you're already inside another app, press first to get back to MAIN MENU.
Press (SIMUL) for simultaneous equations. On the next screen, pick the number of unknowns with the F-keys: press for 3 unknowns. The Casio opens a coefficient grid, one row per equation, with columns a, b, c (the coefficients) and d (the constant).
Enter each equation's coefficients of x, y, z followed by the constant, pressing after each value. The missing y term in the first equation is a 0: row 1 is 1, 0, 1, 5, row 2 is 2, -1, 3, 12, and row 3 is -1, 4, 1, 5. Use for the negative coefficients.
Press (SOLVE). The Casio solves the system and lists the unknowns.
x=2, y=1, and z=3.
Your turn
Work each one on your calculator, then check the answer.
- 1
Solve the system 2x+z=8, x−y+2z=8, 3x+2y−z=5.
- 2
Solve the system x+y+2z=4, 3y−z=11, 2x−y+z=−7.
- 3
Solve the system 4x−y+z=0, x+3z=−5, 2x+y−z=6.