Some of the numerical expressions that we can form are:

(I) `27`

`=(4-2+1)^3`

`=3^2(4-1)`

`=(3^4)/(2+1)`

(II)`34`

`=4!+3^2+1`

(III) `38`

`=((4+1)!)/3-2`

(IV) `42`

`=(4+2+1)xx3!`

`=(3+4)xx(2+1)!`

`=((4+1)!)/3+2`

(V) `44`

`=4!xx2-3-1`

(VI) 47

`=4^2xx3-1`

`=2^4xx3-1`

(VII) `43`

`=4!*2 - 3!+1`

If each number must be used once, this is only possible if we can combine numbers. Please ensure that your rules are clear when establishing the initial question.

27: 23 + (4/1)

34: 34 / 1^2

38: 42 - 3 - 1

42: 42 x 1^3

43: 42 + 1^3

44: 43 + 1^2

47: 41 + 2x3