Assembler (B-A)*C

data segment
    A db 5
    B db 2
    C db 5
ends

; (B-A)*C

code segment
start:

    mov dx, data
    mov ds, dx

    mov dl, A
    sub dl, B

    mov al, dl
    mov ah, 0
    mul C
    AAA

    mov bx, ax

    add bh, 30h
    mov dl, bh
    mov ah, 2
    int 21h

    add bl, 30h
    mov dl, bl
    mov ah, 2
    int 21h

    mov ax, 4c00h
    int 21h

ends

end start