Using TI's Equation Solver

Date: 09/27/1999 at 20:28:59
From: Ashley
Subject: Pre-algebra

Use a TI-82 to solve each equation below.

  a. x - 9 = 0
  b. 2x = 0
  c. 3x - 6 = 0

Date: 09/29/1999 at 19:29:32
From: Doctor Sandi
Subject: Re: Pre-algebra

Hi Ashley, 

I have a TI-83 and might be able to help you.

Do you have a [MATH] button? When you push the [MATH] button does it 
give you a list of options like Frac, Dec, etc? If you arrow down, one 
of them should say "Solver." This is the one we'll be using.

So, press the [Solver] button. You should now see a screen that says 
"bound" among other things. Press up with the arrow keys.

Now it should say Equation Solver, eqn: 0 =.

Press [Clear] to clear what is already there. Now let's do the first 
of your equations, x - 9 = 0. Obviously what we need to find here is 
x. Type in "x - 9" without the quotation marks. I will use them to 
state what you are typing into the calculator.

Press your down arrow key. For now, ignore whatever it says there. To 
find the answer, make sure that your cursor is flashing just after 
"x =" . To find the answer to any equations, your cursor must be in 
this position.

Now press the [Alpha] key plus [Enter], which you will see has "solve" 
written above it. After doing that you will see that the flashing 
cursor is on the number 9, and that it is saying x = 9.

I'll leave (b) to you. Let's do the same thing with (c): 3x - 6 = 0.

So, completely clearing your calculator (I have turned mine off and on 
again), go to [MATH] and choose Solver. Don't worry about any of the 
numbers there; they are there from the previous calculations. Press 
the up arrow to take you to the Equation Solver screen where it says 
eqn: 0 = (it will say x = 9). In here put 3x - 6. Press [Enter]. 
Ignore the answers you see on the screen after you have pressed enter. 
Now press [Alpha] and [Enter] ("Solve.") The answer you should get is 
2, which is true, isn't it? We can check because 3 * 2 - 6 = 0.

This is the way that the equation solver is used on the calculator. It 
shouldn't be different between our two calculators. If it is, please 
feel write back, but I doubt that you will have any problems.

The only thing to remember about this method of solving equations is 
that when you enter the equation it expects you to enter it in terms 
of 0 = something. So if you had 3x = 6, for example, you would need to 
transpose it to 3x - 6 = 0.  In that way you are entering an equation 
that equals zero, which is the only way that the calculator will 
accept the problem.

I hope that this has helped you. If not, please feel free to write 
back to Ask Dr. Math.

- Doctor Sandi, The Math Forum
  http://mathforum.org/dr.math/