解方程.120x-20x=40; 30%x=120; 17%x+10=27.
第1个回答 推荐于2016-09-08
(1)120x-20x=40
100x=40
100x÷100=40÷100
x=0.4;
(2)30%x=120
30%x÷30%=120÷30%
x=400;
(3)17%x+10=27
17%x+10-10=27-10
17%x÷17%=17÷17%
x=100本回答被提问者采纳
100x=40
100x÷100=40÷100
x=0.4;
(2)30%x=120
30%x÷30%=120÷30%
x=400;
(3)17%x+10=27
17%x+10-10=27-10
17%x÷17%=17÷17%
x=100本回答被提问者采纳