If Adam buys 3 stickers and 4 beads, it costs $32.80.
If Adam buys 4 stickers and 3 beads, he will need another $3.70.
- Find the cost of 1 sticker and 1 bead.
- Find the cost of 1 sticker.
- Find the cost of 1 bead.
(a)
3 stickers + 4 beads = 32.80 --- (1)
4 stickers + 3 beads = 32.80 + 3.70 = 36.50 --- (2)
(1) + (2)
7 stickers + 7 beads = 69.30 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 69.30 ÷ 7 = 9.90 --- (4)
Cost of 1 sticker and 1 bead = $9.90
(b)
4 stickers + 3 beads = 36.50 --- (2)
(4)
x 3 3 stickers + 3 beads = 3 x 9.90 = 29.70 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 36.50 - 29.70
4 stickers - 3 stickers + 3 beads - 3 beads = 6.80
1 sticker = 6.80
Cost of 1 sticker = $6.80
(c)
Substitute 1 sticker = 6.80 into (4).
1 sticker + 1 bead = 9.90
6.80 + 1 bead = 9.90
1 bead = 9.90 - 6.80 = 3.10
Cost of 1 bead = $3.10
Answer(s): (a) $9.90; (b) $6.80; (c) $3.10