解方程
(1)x÷15+0.4=x÷12-0.1?????????
(2)150.5-4x+0.5x=7.
网友回答
解:(1)x÷15+0.4=x÷12-0.1,
????????? x+0.4=x-0.1,
???? x+0.4-x=x-0.1-x,
?????????? 0.4+0.1=x-0.1+0.1,
?????????? 0.5×60=x×60,
???????????????? x=30;
(2)150.5-4x+0.5x=7,
????????150.5-3.5x=7,
?? 150.5-3.5x+3.5x=7+3.5x,
?????????? 150.5-7=7+3.5x-7,
??????? 143.5÷3.5=3.5x÷3.5,
???????????????? x=41.
解析分析:(1)先化简,再根据等式的性质,在方程两边同时减去x,再加上0.1,最后乘上60求解,
(2)先化简,再根据等式的性质,在方程两边同时加上3.5x,再减去7,最后除以3.5求解.
点评:本题考查了学生根据等式的性质解方程的能力,注意等号对齐.