解方程 6×1.5+5X=1210-0.35X=75X-×6=7.5.
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解:(1)6×1.5+5x=12,
????????????? 9+5x=12,
??????????? 9+5x-9=12-9,
????????????????5x=3,
???????????? 5x÷5=3÷5,
???????????????? x=;
(2)10-0.35x=7,
10-0.35x+0.35x=7.2+0.35x,
???? 7.2+0.35x=10,
?7.2+0.35x-7.2=10-7.2,
???????? 0.35x=2.8,
???0.35x÷0.35=2.8÷0.35,
???????????? x=8;
(3)5x-×6=7.5,
?????? 5x-1.5=7.5,
?? 5x-1.5+1.5=7.5+1.5,
?????????? 5x=9,
??????? 5x÷5=9÷5,
??????????? x=1.8.
解析分析:(1)6×1.5+5x=12,先计算6×1.5=9,再利用等式的性质,方程的两边同时减去9,再除以5即可;(2)10-0.35X=7利用等式的性质,方程的两边同时加上0.35x,再减去10,除以0.35即可;(3)5X-×6=7.5,×6=1.5,再利用等式的性质,方程的两边同时加上1.5,再除以5即可.
点评:此题考查利用等式的性质解方程,注意等号对齐.