Set 4.5x - 9(1-x) to Equal -1 with TI 83 Calculator

[Kombaiyashii]

Hi.

I would like to make the answer equal -1

here's the formula:

4.5(x) - 9(1-x)

How do I set this to equal -1? (This isn't homework, I'm working out some poker math and am not very good at this type of thing.) I use a TI 83 calculator.

 

[SteamKing]

It's the same as 4.5(x) - 9(1-x)+1 = 0

Take a hint from me:
If you want to learn math, set your calculator aside.

 

[HallsofIvy]

To "set" something to -1 means to write "= -1" at the end! So to "set" 4.5x- 9(1- x) to -1 is just to write 4.5x- 9(1- x)= -1. If you mean "find the value of x that makes this true", use the usual "rules" of algebra. First multiply out those parentheses:
4.5x- 9+ 9x= -1
Add the terms in x, 13.5x- 9= -1. Now add 9 to both sides, then divide both sides by 13.5.

Using a calculator to do that is like using a calculator to add "1+ 1" (and I have seen people do that!).

 

[Mark44]

Take a hint from me:
If you want to learn math, set your calculator aside.

+1 to that!

 

[CellCoree]

To set the equation equal to -1 on a TI 83 calculator, follow these steps:

1. Enter the equation into the calculator: 4.5x - 9(1-x)
2. Press the "Enter" button to see the current answer.
3. Press the "2nd" button, then the "Math" button.
4. Scroll down to "fnInt(" and press "Enter".
5. Enter the equation again, but this time add "-1" at the end: 4.5x - 9(1-x) -1
6. Press the "Enter" button to see the new answer.
7. The calculator will display "fnInt(" at the beginning of the equation. Press the "Enter" button again to solve for x.
8. The calculator will give you the value of x that makes the equation equal to -1.