5×x=500-460
y:23=36:12
1000-x=600-53

5·x = 500-460

5·x = 40

x = 40:5

x = 8

y:23 = 36:12

y:23 = 3

y = 3·23

y = 69

1000-x = 600-53

1000-x = 647

-x = 647-1000

-x = -353

x = 353