add & subtract values from userform to specific column in sheet

hi, i have this code for mr. sintek i would amending by make it add & subtract values i have two userform first add values to col e and the same thing the userform 2 but subtract when i use data from multiple combobox based on data in sheet1 from a2:d and fill the value in textbox should change this brand add as in userform1 or subtract as userform2

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