2.4×3= 0.6a+5.4a= 8.2×0.1= 10.7-2.8=
+ = 6÷0.02= - = 6x-5x=
①5x+7=28
②6.6x+5.4x=19.2
③4x-0.7 =8.1
④12+5x=72
⑤7.5+2.5x=15
⑥x-0.85x=3