(1)4/7×8/9+8/7×5/9
=4/7×8/9+4/7×10/9
=4/7×(8/9+10/9)
=4/7×2
=8/7
(2)3÷3/4-3/4÷3
=3×3/4-3/4×1/3
=3/4×(3-1/3)
=3/4×8/3
=2