求未知数x的值: (1)x﹣x= (2)8:x=: (3)8×1.5+0.4x=20.
7-4= 9-5= 5+5= 3+3= 7-7= 8-7=
5+3= 5-3= 6-6= 8+1= 9+1= 10-4=
6-5= 10-5= 4+3=2+2= 2+1= 6-5=
8+2= 7-5= 7+2=10-10= 9-9= 1+1=
10-3= 6+1= 9+1= 8-3= 9-6= 4+3=