Casio FX-85ES PLUS Manual De Usuario

E-20

You can use the following procedure in the EQN Mode to solve simultaneous 
linear equations with two or three unknowns, quadratic equations, and cubic 
equations. 

1. Press 

(EQN) to enter the EQN Mode. 

2. On the menu that appears, select an equation type. 

Simultaneous linear equations with two 
unknowns

(a

n

X + b

n

Y = c

n

)

Simultaneous linear equations with 
three unknowns

(a

n

X + b

n

Y + c

n

Z = d

n

)

Quadratic equation

(aX

2

 + bX + c = 0)

Cubic equation

(aX

3

 + bX

2

 + cX + d = 0)

3. Use the Coefficient Editor that appears to input coefficient values. 

• To solve 2

2 

+ 

 – 3 = 0, for example, press 

 in step 2, and then input  

the following for the coefficients (

 = 2, 

 = 1, 

 = –3): 2

1

3

. 

• To change a coefficient value you already have input, move the cursor 

to the appropriate cell, input the new value, and then press 

. 

• Pressing 

 will clear all of the coefficients to zero. 

Important: The following operations are not supported by the Coefficient 
Editor: 

;, ;(M–), B(STO). Pol, Rec, and multi-statements 

also cannot be input with the Coefficient Editor. 

4. After all the values are the way you want, press 

.

• This will display a solution. Each press of 

 will display another 

solution. Pressing 

 while the final solution is displayed will return to 

the Coefficient Editor. 

• You can scroll between the solutions using the 

A and D keys. 

• To return to the Coefficient Editor while any solution is displayed, press 

.

Note:  • Even if Natural Display is selected, the solutions of simultaneous 
linear equations are not displayed using any form that includes 

.  • Values 

cannot be converted to engineering notation on the solution screen. 

Press 

(EQN) and then select an equation type from the menu that 

appears. Changing the equation type causes the values of all Coefficient 
Editor coefficients to change to zero. 

 

 + 2

 = 3, 2

 + 3

 = 4

 

(EQN)(a

n

X + b

n

Y = c

n

) 

 

                                             1 

 2  3 

 

                                             2 

 3  4  

 

                                                               

  

 

 

                                                               

A