(-1/63)÷(1/9-2/7+2/3-4/21)

问题描述:

(-1/63)÷(1/9-2/7+2/3-4/21)

(-1/63)÷(1/9-2/7+2/3-4/21)
= (-1/63)÷(1/9-6/21+6/9-4/21)
= (-1/63)÷(7/9-10/21)
= (-1/63)÷(49/63-30/63)
= (-1/63)÷(19/63)
=-1/19