Question

X•63=63. y:549=1. 1+c=56*1. 280-y=420:420

Answer 1

X- 1
Y-549
C-56*0
Y-279

Answer 2

С-55

Answer 3

х* 63 = 63
63х = 63
    х = 1
-------------------
у : 549 = 1
у = 1 * 549
у = 549
-------------------
1 + с = 56 * 1
1 + с = 56
с = 56 - 1
с = 55
-------------------
280 - у = 420 : 420
280 - у = 1
у = 280 - 1
у = 279