f

dosseg
.model small
.stack 100h
.data
K equ 616h
A dd 12345678h
B dw 5678h
C dw 7654h
D db 10h
E db 77h
X dd 00h
R1 dw 00h
R2 dw 00h
.code
start:
  mov ax, @data
  mov ds, ax
  ; A/B
  mov ax, word ptr[A]
  mov dx, word ptr[A+2]
  div B
  mov R1, ax
  ;D*E
  xor ax, ax
  mov al, D
  mul E
  mov R2, ax
  ; C2-R2
  mov ax, C
  sbb ax, R2
  adc ax, K
  add ax, R1
  mov word ptr[X], ax
  mov ah, 4ch
  int 21h
  end start