Question

What should be added to 5 3/7 to get 12

Answer 1

38/7+x=12
x=12-38/7
x=12-5.42
x=6.58

Answer 2

did you mean,
5hole 3/7 to get 12
x+5 3/7= 12
x+38/7=12
x=12-38/7
x=84-38/7
x= 46/7
x=4 6/7 ans or 6.58 in decimal