(59a+2023)/50=2758
59a+2023=17900
59a=135877
a=2303
b/5*501-1=251000
501b/5=251001
501b=1255005
b=2505
4160/65+c-1938=670
64+c-1938=670
-1874+c=670
c=670+1874
c=2544
(130+10870)/11+2000-d=465
11000/11+2000-d=465
1000+2000-d=465
3000-d=465
-d=-2535
d=2535