问题描述:

解方程.
x+10.5=79.7?????????????????????????
5x=0.25
7÷x=0.5?????????????????????????????
x÷1.1=3.

网友答案:
解:(1)x+10.5=79.7,
??? x+10.5-10.5=79.7-10.5,
??????????????x=69.2;

(2)5x=0.25,
? 5x÷5=0.25÷5,
????? x=0.05;

(3)7÷x=0.5,
? 7÷x×x=0.5×x,
?????0.5x=7,
0.5x÷0.5=7÷0.5,
????????x=14;

(4)x÷1.1=3,
x÷1.1×1.1=3×1.1,
?????????? x=3.3.

解析分析:(1)根据等式的性质,两边同减去10.5即可;(2)根据等式的性质,两边同除以5即可;(3)根据等式的性质,两边同乘x,得0.5x=7,两边再同除以0.5即可;(4)根据等式的性质,两边同乘1.1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.
相关阅读:
Top