①8.69﹣(2.69+3.25)
②
③4×0.56×25
④
①x+x=42
②=
①0.53×2.5+
②25×0.032×12.5
③ [()×]
④6.83+17.9﹣0.83+32.1
4,10,17,25,34,,55。