用运算定律和性质填一填ac-bc=()·c 顺便用简便方法算下这题4759+1998=还有一题脱式计算39+0.18*80%-62.5%/5=

用运算定律和性质填一填ac-bc=()·c 顺便用简便方法算下这题4759+1998=还有一题脱式计算39+0.18*80%-62.5%/5=
用运算定律和性质填一填ac-bc=()·c 顺便用简便方法算下这题4759+1998=
还有一题脱式计算
39+0.18*80%-62.5%/5
=

用运算定律和性质填一填ac-bc=()·c 顺便用简便方法算下这题4759+1998=还有一题脱式计算39+0.18*80%-62.5%/5=
用运算定律和性质填一填ac-bc=(a-b)·c
顺便用简便方法算下这题
4759+1998=4759+2000-2=6757
39+0.18*80%-62.5%/5
=39+0.144-0.125
=39.019