523﹣23×7
4.97+6.38+5.03﹣4.38
60×()
×3.2+5.6×0.5+1.2×50%
()÷
①2x﹣4×0.5=4
②:=x:
a= b= c= d= e= f=
,a, ,b,
,d, ,e,