问题 解答题
解方程
0.9X=2.7X-12.56=7.8X÷3.5=71.25+X=4.
答案

①0.9X=2.7,

0.9X÷0.9=2.7÷0.9,

X=3;

②X-12.56=7.8,

X-12.56+12.56=7.8+12.56,

X=20.36;

③X÷3.5=7,

X÷3.5×3.5=7×3.5,

X=24.5;

④1.25+X=4,

1.25+X-1.25=4-1.25,

X=2.75.

问答题
单项选择题