There are 2 equation. First let 49 cent stamps be f and 34 stamps be t. One equation would be f+t=40 the other one would be .49f+.34t=17.35. You can do substitution if you want or elimination. Put the two in line 49f+34t=1735 f+t=40----> elimination -34(f+t=40)--> solve
49f+34t=1735 -34f-34t=-1360 --->solve --------------------- 15f =375--> divide f=25 Then put this on the first equation to find the other answer.
