3/14х-59/100=8/21х-124/100

3/14х-59/100=8/21х-124/100
3/14х - 59/100 - 8/21х + 124/100 = 0
3/14х - 8/21х + 124/100 - 59/100 = 0
9/42х - 16/42х + 65/100 = 0
-7/42х = -65/100
-1/6х = -65/100
1/6х = 13/20
х = 13/20 : 1/6
х = 13/20 * 6
х = 78/20
х = 3 18/20
х = 3,9

ОТВЕТ: 3,9