解方程.
(1)x÷0.26=0.52
(2)9x-2x=21.7
(3)3.18×2-2x=4.26
(4)0.25x+3.75=12.
解方程:(1)x÷0.26=0.52
x÷0.26×0.26=0.52×0.26,
x=0.1352;
(2)9x-2x=21.7,
7x=21.7,
7x÷7=21.7÷7,
x=3.1;
(3)3.18×2-2x=4.26,
6.36-2x=4.26,
2x=6.36-4.26,
2x÷2=2.1÷2,
x=1.05;
(4)0.25x+3.75=12.
0.25x+3.75-3.75=12-3.75,
0.25x÷0.25=8.25÷0.25,
x=33.
分析:根據(jù)等式的性質,等式的兩邊同時加上或減去相同的數(shù),等式仍然成立;等式的兩邊同時乘或除以相同的數(shù)(0除外),等式仍然成立;據(jù)此解方程即可.
點評:此題主要根據(jù)等式的性質解方程,注意書寫格式,等號對齊.