How do I use the solve function

Hello,
First of all, you have to set the mode to EQUATION by pressing [MODE][5:Equation]. When you do that, you are offered 4 choices of equation types to solve.

PART 1 a_n*X+b_n*Y=C_n.

In this type, you have only 2 unknows, X, Y, the others are coefficients. When this mode is selected, you are given access to a what looks like a matrix.
The top row, inaccessible to you, displays headings a, b, c.
The first column, also inaccessible to you numbers the lines as (1 and 2)
First line
Enter the coefficient of X in the first equation, a_1, and press [=] Cursor moves to the dark rectangle under the b heading.
Enter the coefficient of Y, (b_1) in the first equation and press [=] Cursor moves to the dark rectangle under heading c.
Enter the constant term in the first equation, C_1, and press [=]

At this stage you have finished entering the coefficients and constant term of the first linear equation of your system, namely
a_1*X+b_1*Y= C_1

After you enter C_1 and press [ENTER] the cursor moves to the

Second Line

On this line, just as in the previous one, you enter a_2, b_2 and c_2 Once you finish entering all coefficients and constant terms you press [ENTER].

Calculator does its thing and returns with a solution and displays at the top left of the screen
X=
and on the bottom right the value for X ( a fraction or a decimal number)
Press [=] again and the screen displays the value of the second unknown Y.
If you press [=] a third time the claculator takes you back to the entry screen to modifiy coefficients and constant terms.

Exemple a_1=6 b_1=3 c_1=7 a_2=5 b_2=8.3 c_2=1
X= 19/12 To convert it to decimal press [S<->D] to get 1.58333 Y=-5/6 To convert it to decimal press [S<->D] to get -0.8333333

PART B a_n*X+b_n*Y+c_n*Z =D_n This is a linear system in 3 unknowns X, Y, X.
It requires
a_1, b_1, c_1, and d_1
a_2, b_2, c_2, and d_2
a_3, b_3, c_3 and d_3.
Procedure to enter the coefficients and constant terms is the same as above, but due to the limited screen, you have to use right arrow to access the places where you enter d_1, d_2. d_3.

When finished you have to press [=] 1 time to get X, a second time to get Y, and a third time to get Z.

PART C aX^2 + bX +c=0 (quadratic equation)
You enter a, b, and c in the template.

When finished press[ENTER] once to get X1, and a second time to get X2.

PART D aX^3 +bX^2+cX+d =0 (cubic equation)

Same procedure as Part C, except that you have to enter a, b, c, and d in template and press [=] 1 time to get X1, a second time to get X2, and a third time to get X3.

Hope it helps.

PS to the power that be of this site, if you are listening: We ought to have prompts to confirm the post before validating it. We ought to be able to correct typos, errors; to amend what we entered.