(x + 1)/58 + (x + 2)/57 = (x + 3)/56 + (x + 4)/55
(x + 1)/58 + 1 + (x + 2)/57 + 1 = (x + 3)/56 + 1 + (x + 4)/55 + 1
(x + 59)/58 + (x + 59)/57 = (x + 59)/56 + (x + 59)/55
=> (x + 59)/58 + (x + 59)/57 - (x + 59)/56 - (x + 59)/55 = 0
=> (x + 59).(1/58 + 1/57 - 1/56 - 1/55) = 0
Do 1/56 > 1/58; 1/55 > 1/57 => 1/58 + 1/57 - 1/56 - 1/55 khác 0
=> x + 59 = 0
=> x = -59
(x + 1)/58 + (x + 2)/57 = (x + 3)/56 + (x + 4)/55
(x + 1)/58 + 1 + (x + 2)/57 + 1 = (x + 3)/56 + 1 + (x + 4)/55 + 1
(x + 59)/58 + (x + 59)/57 = (x + 59)/56 + (x + 59)/55
=> (x + 59)/58 + (x + 59)/57 - (x + 59)/56 - (x + 59)/55 = 0
=> (x + 59).(1/58 + 1/57 - 1/56 - 1/55) = 0
Do 1/56 > 1/58; 1/55 > 1/57 => 1/58 + 1/57 - 1/56 - 1/55 khác 0
=> x + 59 = 0
=> x = -59