Question 1004580
x+y= 64; y= 64-x
1x+10y= 199 Substitute for y:
1x+10(64-x)= 199
1x+640-10x= 199
-9x= -441
x= -441/-9
x= 49
He has 49 $1 bills and 64-49= 15 $10 bills