(-12又三分之二)÷1.4-(-8又三分之一)÷(-1.4)+9又三分之一÷1.4
=(-38/3)÷14/10-(-25/3)÷(-14/10)+28/3÷14/10
=(-38/3)×5/7-25/3×5/7+28/3×5/7
=5/7×(-38/3-25/3+28/3)
=5/7×(-35/3)
=-25/3
=-8又3分之1
(-12又三分之二)÷1.4-(-8又三分之一)÷(-1.4)+9又三分之一÷1.4
=(-38/3)÷14/10-(-25/3)÷(-14/10)+28/3÷14/10
=(-38/3)×5/7-25/3×5/7+28/3×5/7
=5/7×(-38/3-25/3+28/3)
=5/7×(-35/3)
=-25/3
=-8又3分之1