解方程． x-3/8=1/2 4-0.7x=3.79．
问题描述：
解方程．
x-
=3 8
1 2
4-0.7x=3.79．
答
（1）x-
=3 8
1 2
x-
+3 8
=3 8
+1 2
3 8
x=
；7 8
（2）4-0.7x=3.79
4-0.7x+0.7x=3.79+0.7x
3.79+0.7x=4
3.79+0.7x-3.79=4-3.79
0.7x=0.21
0.7x÷0.7=0.21÷0.7
x=0.3．