Đáp án:
Giải thích các bước giải:
$\dfrac{1998 × 1996 + 1997 × 11 + 1985}{1997 × 1996 - 1995 × 1996}$
`=` $\dfrac{1998 × 1996 + (1996 + 1) × 11 + 1985}{1996 × (1997 - 1995)}$
`=` $\dfrac{1998 × 1996 + 1996 × 11 + 11 + 1985}{1996 × 2}$
`=` $\dfrac{1998 × 1996 + 1996 × 11 + 1996}{1996 × 2}$
`=` $\dfrac{(1998 + 11 + 1)}{1996 × 2}$
`=` `1005`