48: 8+32-54: 6 , (35+65)-21-(16+8) , 8*6+35: 5-19+2*5 , 18: 3*4+27+40: 8

1)48:8+32-54:6=29
48:8=6
54:6=9
6+32=38
38-9=29
2) (35+65)-21-(16+8)=55
35+65=100
16+8=24
100-21=79
79-24=55
3)8*6+35:5-19+2*5=46
8*6=48
35:5=7
2*5=10
48+7=55
55-19=36
36+10=46
4)18:3*4+27+40:8=56
18:3=6
6*4=24
40:8=5
24+27=51
51+5=56