(2/9×3/4－1/12)×4
=（1/6-1/12)×4
=1/6×4-1/12×4
=2/3-1/3
=1/3
2/9×3/5+2/5×2/9
=2/9×(2/5+3/5)
=2/9×1
=2/9
85×96－85×95
=85×(96-95)
=85×1
=85