Mathtype 6.9b [portable] -

: Use the palettes to select symbols (fractions, roots, integrals) and type your variables. : Once finished, close the window or click to place the equation at your cursor's position. Edit Later

MathType 6.9b is a legacy desktop version of the popular equation editor, widely recognized for its integration with Microsoft Office 2013 and 2016 mathtype 6.9b