解方程:
(1)10(200X+X)=11×200X-22.8
(2)=3+.
网友回答
解:(1)10(200X+X)=11×200X-22.8,
??????????????? 2010X=2200X-22.8,
????????? 2010X-2010X=2200X-22.8-2010X,
??????????? 190X-22.8=0,
?????? 190X-22.8+22.8=0+22.8,
???????????????? 190X=22.8,
??????????? 190X÷190=22.8÷190,
??????????????????? X=0.12;
(2)=3+,
????? 5X-10=3+2X+2,
? ?5X-10+10=3+2X+2+10,
???????? 5X=2X+15,
????? 5X-2X=2X+15-2X,
???????? 3X=15,
??????3X÷3=15÷3,
????????? X=5.
解析分析:(1)原式变为2010X=2200X-22.8,根据等式的性质,两边同减去2010X,得190X-22.8=0,两边同加上22.8,再同除以190即可;(2)化简原式为5X-10=3+2X+2,根据等式的性质,两边同加10,得5X=2X+15,两边同减2X,得3X=15,再同除以3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.