How do you type an equal sign on the TI 84 calculator

You cannot. To evaluate an expression (not an equation or an equality) key it in and press ENTER.

Press 2ND [TEST] 1 .

The equal sign of the TI83/84/Plus is a relational operator like less than , greater than, less than or equal to) You use it when you are testing if two values (numbers, expressions, or matrices) are equal.
For example, if in one your programs what you do at a certain time depends on the equality of two expressions, you test the equality by a statement :
If A=B do this action.

You don't need "equal" to finish a operation, just hit ENTER.

You, or someone else played with INEQALZ (inequalty graphing) applications. The problem is thet it remains in memory and takes over the graphing duties from the native OS. If you do not want Inequalz to manage the graphing, just kick it out of memory.
Press [APPS¨] key.
Use arrows to scroll through the list of APPS.
Locate INEQALZ and highlight it.
Press [ENTER]
In the new screen INEQALZ RUNNING, press the number that corresponds to the option Uninstall.

If you wan to solve an equation using the SOLVE feature you enter it as follows (your example)
You should rewrite it as 5/4*X-18+3 (= 0). Implicitly, the calculator assumes that the right side is ZERO and you do not enter any right side nor an equal sign.
Type in
5/4 [*] [X,T,theta, n] -18 +3 [ALPHA] [ENTER] (SOLVE)
You should get an answer -780/47 or the decimal equivalent (depending on display mode.)

You can access the = sign through the CATALOG of command.
Press [2nd][0]
Use Up arrow to scroll through the Catalog index from the bottom. You will eventually find the = sign.

hello sir, Press "second" "math", and it should be the first thing listed. If you need other commands hit "second" "0" that will enter the catalog and you can press any letter (without hitting alpha) to jump to that letter in the list. Please click on the following link to see the manual of the TI-84 Plus Calculator: http://education.ti.com/guidebooks/graphing/84p/TI84PlusGuidebook_Part2_EN.pdf
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ok well go to the 'y=' button
type in the equation and make sure that the equals sign after y has like a black box around it, making the actual = white. so make sure both of those = signs of the 2 equations that you want to graph are like that, and thats about it.

press 2nd, then math. It will bring you to a menu with =, not equal, >, <, and that kind of stuff