The law should be that four numbers should be multiplied and subtracted, and four numbers should be subtracted.

47= 1*3*4*5- 1-3-4-5

14= 1*2*3*4- 1-2-3-4

Third, I think you are wrong or have typed the original question wrong. It should be 1.4.5.6. This makes it 104.

1*5*4*7- 1-5-4-7= 123