Answer:
3
Step-by-step explanation:
x will represent the number of $50 bill
y is the $10 bills
y+4=x
50x+10y=380
Now we fill in x
[tex]50(y+4)+10y=380\\50y+200+10y=380\\60y+200=380[/tex]
Subtract 200 from both sides
[tex]60y=180[/tex]
Dide both sides by 60
[tex]y=3[/tex]
Since y represents the $10 bills then Peter has 3 of them
Hope this helps