4x﹣234=58
①7.63﹣0.54﹣(2.46﹣1.37)
②2.1×40%+ ×2.1
③ ÷[( + )× ]
500-213= 10÷10%= 0.25+2.83= 1.25×0.8= 3.7-3.7÷3.7=
92-33= + = × = 9÷ = ( - )×20=