(1)0.25×6.7×4=0.25×4×6.7=6.7
(2)2/3×7/12÷7/8=2/3×7/12×8/7=1/3×1/3×4=4/9
(3)1000-540÷18×24=1000-540÷4/3=1000-720=280
(4)(5/12+1/19)×12+7/19=5+12/19+7/19=5+1=6
(1)0.25×6.7×4=0.25×4×6.7=6.7
(2)2/3×7/12÷7/8=2/3×7/12×8/7=1/3×1/3×4=4/9
(3)1000-540÷18×24=1000-540÷4/3=1000-720=280
(4)(5/12+1/19)×12+7/19=5+12/19+7/19=5+1=6