Why LaTeX helps
LaTeX lets you write mathematics as plain text instead of drawing symbols. Because it is text, a screen reader can read it, and you can type it with an ordinary keyboard.
Mathematical expressions are written between dollar signs. For example, $x + y$ represents x plus y.
Common notation
A fraction is written as \frac{a}{b}, which reads as a over b. A power uses the caret: x^2 is x squared. A subscript uses the underscore: x_1 is x sub one.
A square root is \sqrt{x}. Greek letters are spelled out with a backslash, such as \alpha, \beta, and \pi.
A worked example
The quadratic formula in LaTeX is x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}.
Read aloud, that is x equals negative b, plus or minus the square root of b squared minus four a c, all divided by two a. Writing it as text keeps every part unambiguous for a screen reader.