MM

expr.asm

include io.h

cr equ 0dh
lf equ 0ah

data segment
la db cr,lf,'Enter a',0
lb db cr,lf,'Enter b',0
l1 db cr,lf,'Enter x',0
ly db cr,lf,'Enter y',0
f dw 40 dup(?)
a db ?
b db ?
x db ?
y db ?
data ends

code segment
assume cs: code, ds:data
start: mov ax,data
mov ds,ax

output l1
inputs f,40
atoi f
mov x,ax

output ly
inputs f,40
atoi f
mov y,ax

output la
inputs f,40
atoi f
mov a,ax

output lb
inputs f,40
atoi f
mov b,ax

add dx,a ;dx = a+b
mov cx,a
sub cx,ax ;cx = a-b
mov bx,x
mov ax,y
add ax,bx ;ax = x+y
sub bx,y ;bx = x-y

imul cx     ;ax = (x+y)(a-b)
mov cx,ax   ;cx = (x+y)(a-b)

mov ax,bx;
imul dx 
mov bx,ax  ;bx = (x-y)(a+b)

mov ax,cx;

cwd
idiv bx

itoa f,ax
output f

quit:
mov al,00h
mov ah, 4ch
int 21h

code ends
end start