X = 0.6888
Multiply both sides by 10:
10X = 6.8888
Subtract:
10X = 6.8888 - X = 0.6888 = 9X = 6.2
X = 6.2/9
Remove decimal by multiplying by 10
X = 62/90
Divide both numbers by 2:
X = 31/45
K = 31
