①
②
③ =3:2
③
④
⑤(3x+2)+2[(x-1)-(2x+1)]=6
⑥
12x+1.5=5.1
:x=3:12
① ②
①1.5x-2.8=4.7
③12: =
x﹣ =
x+ x=
x:2.1=0.4:0.9.