You want a long mathematical formula of numerator and denominator. In the final analysis, you want to lengthen the dividing line.

Let's take the chemical equation long equal sign as an example.

Open the Yi Tu Formula Editor, or directly enter the Yi Tu Formula Editor on the web page and enter the editing area. Use the keyboard to enter numbers and element characters. Pay attention to switching to English input method. Use uppercase and lowercase English letters to represent element symbols. Subscript number identification should be identified by "semicolon, root sign and subscript template" in the function bar. In this way, the rapid input of molecular formulas 2KMNO4, K2MNO4, MNO2 and O2 is completed.

Find the "Arrow Symbol" template in the function bar, move the cursor to the corresponding rising arrow symbol, and click "Insert".

Insert a "rectangular template" between molecular formulas 2KMNO4 and K2MNO4, as shown in the following figure.

Insert the double bottom line template in the bottom line template and the top line template in the upper part of the matrix template, as shown in the figure below.

Find the triangle symbol in the relationship and operator symbol template and insert it at the top of the double underline. If you want to present a good-looking effect, you can put the cursor on the triangle once, press the space bar to lengthen it, and then adjust the position of the triangle to present the desired effect, as shown below.