Question 154012
.40*2x+.16x=5.76
.80x+.16x=5.76
.96x=5.76
x=5.76/.96
x=6 16 cent stamps used.
2*6=12 40 cent stamps used.
proof
.40*12+.16*6=5.76
4.8+.96=5.76
5.76=5.76