Look at this: https://m.tb.cn/h.eVFTXAr?sm=4dab3f
https://blog.csdn.net/gsh_hello_world/article/details/56277182
https://blog.csdn.net/gsh_hello_world/article/details/81335955
converts MathType formula LaTeX code method are summarized below:
1. Open MathType editing software, after editing the equation, click on "Preferences (P)" menu, select "cut and paste presets (C)". 
2. cut and paste preferences dialog pop, click the last one, and remove the "data in the conversion comprises MathType (D)" in front of the hook, and click "OK."
3. Return to MathType, select the formula, press "Ctrl + C" copy and paste TexStudio can be.
