上题=8×49/9×9/2×1/5+4/7-2/3×4
=196/5+4/7-8/3
=(196×21+4×15-280)/105
=3896/105
下题=(12/6)³x^(6-9)y^(-6-9)
=8x^(-3)y^(-15)
=8/(x³y^15)
上题=8×49/9×9/2×1/5+4/7-2/3×4
=196/5+4/7-8/3
=(196×21+4×15-280)/105
=3896/105
下题=(12/6)³x^(6-9)y^(-6-9)
=8x^(-3)y^(-15)
=8/(x³y^15)