Verified answer

task/30419245  

1) (237 -23)/900 +43 /450 =214/900 +43/450 = 107/450+43/450 =

= (107 +43)/450=150/450 = 1/3

2) (561 - 5)/990 - 113/495 =556 /990 - 113/495=278/495 -113/495 =

=(278-113) = 165/495 = 1/3  

3) 1/3 : 1/3 = 1 .                                                        ответ:  1