Yup… that works for those simple equations. For your example you should look into learning some braille, so you can use your existing number system together with a memory palace to encode the formulas. Have a look here:
You then simply use a gas station as your memory palace; or place something that reminds you of it into the first location of the palace. Also, no ambiguity when using braille, so you won’t confuse a badly encoded + with an x, etc.