Because 5+1=2+4=6, then we can make them subtract from each other and multiply it to the remaining numbers to get 0.
3*[(5+1)-(4+2)]=0
Here's another solution!
42+3−5−1=0
42−5∗3−1=0
4∗32−5−1=0
4+15−3+2=0
These are a few possibilities that I came up with.