0.52-x=0.25
x-0.15x=8.5
.
网友回答
解:(1)0.52-x=0.25,
???????0.52-x+x=0.25+x,
???????? 0.25+x=0.52,
??? 0.25+x-0.25=0.52-0.25,
????????????? x=0.27;
(2)x-0.15x=8.5,
?(1-0.15)x=8.5
?????? 0.85x=8.5,
?0.85x÷0.85=8.5÷0.85,
?????????? x=10;
(3):=x:,
??????? x=×,
???? x×5=×5,
????????? x=;
(4)x+2.4×5=14,
???????? x+12=14,
????? x+12-12=14-12,
????????????x=2,
?????????x×2=2×2,
???????????? ?x=4.
解析分析:(1)根据等式的性质,两边同加上x,得0.25+x=0.52,两边同减去0.25即可;(2)运用乘法分配律改写成(1-0.15)x=8.5,即0.85x=8.5,两边同除以0.85即可;(3)先根据比例的性质改写成x=×,再根据等式的性质,两边同乘5即可;(4)先求出2.4×5=12,再根据等式的性质,两边同减去12,再同乘2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.