学了有理数的运算后,老师给同学们出了一题.

1个回答

  • (1)小杨的解法较好;

    (2)19

    17

    18 ×(-9)

    =(20-

    1

    18 )×(-9)

    =20×(-9)-

    1

    18 ×(-9)

    =-180+

    1

    2

    =-179

    1

    2 .