求未知数x。(1)5(x﹣3)=4.5 (2)x:3.6=:
8-x= 3-x=
2x+3x=3.15 3.4x=8.6-1.8
2(200-15x)=70+25x 3(2x+1)=12
0.92×1.41+0.92×8.59 ×-×1.3×11.6-1.6×1.3 ×11.6+18.4×
13×÷ 29÷×15.68+(5.39+4.32) 19.68-(2.97+9.68) 7+(-) 5-(-)