How do you solve simultaneous equation using calculator fx-82MS?

Answer 1

According to the fx-82MS manual (downloadable from the Casio website: http://http://support.casio.com/en/manual/manuallist.php?cid=004) the fx-82MS does not appear to have a built-in simultaneous equation solver - you would have to solve them yourself through algebraic manipulations of the equations.

A different calculator, eg the fx-115MS, which does have built-in simultaneous equation solving would be required. On the fx-115MS the steps are:

[mode][mode][mode] 1 (to get EQN mode)

This then prompts (Unknowns?) for the number of unknowns - either 2 (for 2 equations with unknown x & y: ax + by = c) or 3 (for 3 equations with unknown x, y & z: ax + by + cz = d).

Once selected, you then enter all the coefficients (the a, b, c[, d] for the equations, the subscript telling you which equations (a1, a2, etc). After entering each one, pressing equals [=] will move onto the next coefficient; after the last coefficient has been entered the calculator works out the required value of x and y (and z for 3 unknowns). It displays the value for x; to get the values of the other unknowns use up and down on the navigate/replay key; or press the equals [=] key. Before the last coefficient is entered, you can use up and down on the navigate/replay key to go up and down the coefficients and correct them.

If the given coefficients means there is no unique answer (eg two equations are multiples of each other) a Math ERROR will occur. Pressing [AC] returns to entering the first coefficient (as below).

Once all unknowns have had their values vied, pressing equals [=] on the last one returns to entering the first coefficient (the coefficients previously entered are presented for editing) to allow further equations, or corrections, to be entered.

To leave EQN mode, use: [mode] 1 to return to Comp[utation] mode.

The fx-115MS can also be used to solve quadratic or cubic equations:

Pressing [mode][mode][mode] 1 [right] will bring up a choice of Degree? which can be 2 (for a quadratic) or 3 (a cubic). Here you enter the coefficients as before and the roots of the equation are the answer. If a result has an imaginary value, [shift][=] will alternate between the real and imaginary parts of the current solution (an indicator at the top right of the screen tells you which part it is).