Question 362943
X+Y=345 OR X=345-Y
.02X+.03Y=8.90
.02(345-Y)+.03Y=8.90
6.90-.02Y+.03Y=8.90
.01Y=8.90-6.90
.01Y=2
Y=2/.01
Y=200 3 CENT STAMPS WERE BOUGHT.
345-200=145 2 CENT STAMPS WERE BOUGHT.
PROOF:
,02*145+.03*200=8.90.
2.90+6.00=8.890
8.90=8.90