5.5x-1.3x=12.6?????????????????
3.85+1.5x=6.1
6x-0.9=4.5????????????????????
4×4.5-3x=6.33.
网友回答
解:5.5X-1.3X=12.6,
???????? 4.2X=12.6,
??? 4.2X÷4.2=12.6÷4.2,
??????????? X=3;
???? 3.85+1.5X=6.1,
3.85+1.5X-3.85=6.1-3.85,
?? ??1.5X÷1.5=2.25÷1.5,
???????? ? ? X=1.5;
??? 6X-0.9=4.5,
6X-0.9+0.9=4.5+0.9,
?????6X÷6=5.4÷6,
?????? ? X=0.9;
4×4.5-3X=6.33,
??? 18-3X=6.33,
?????? 3X=18-6.33,
??? 3X÷3=11.67÷3,
??????? X=3.89.
解析分析:根据等式的性质解答,即“等式两边同时乘同一个数,或除以同一个不为0的数,结果仍相等”,“等式两边同时加上(或减去)同一个数(或式子),结果仍相等”.
点评:此题考查了学生解方程的能力,注意等号对齐.