0.6x+3×2.5=67.5÷(x-0.45)=.
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解:(?1)0.6x+3×2.5=67.5,
??????????? 0.6x+7.5=67.5,
??????? 0.6x+7.5-7.5=67.5-7.5,
??????????????? 0.6x=60,
????????? 0.6x÷0.6=60÷0.6,
????????????????? x=100;?
(2)1÷(x-0.45)=5,
÷(x-0.45)×(x-0.45)=(x-0.45),
??????????? x-2.4=1.6,
????????x-2.4+2.4=1.6+2.4,
??????????????? ?x=4,
????????
??????????? x÷=4÷,
??????????????????? x=.
解析分析:(1)把算3×2.5得7.5,根据等式的性质,两边同减去7.56,得6x=60,再同除以6即可;
(2)根据等式的性质,两边同乘x-0.45,得5(x-0.45)=1,x-2.4=1.6,根据等式的性质得出x=4,再同除以即可.
点评:此题考查了根据等式的性质解方程,即等式两边同加、同减、同乘或同除以一个数(0除外),等式的左右两边仍相等;注意等号上下要对齐.