①
②
③
①120×4×0.25×0.7
②51×7.5-49×7.5-1
③(20+9.744÷2.4)×0.5-1.93
④[3.72-0.72×(1.6+2.4)]÷0.1
①+++
②(-+)×24
③1.5×+8.5×
④4×0.8×2.5×12.5
⑤25××40%×
⑥÷[(+)×]