If Adam buys 3 stickers and 4 beads, it costs $40.80.
If Adam buys 4 stickers and 3 beads, he will need another $3.10.
- 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 = 40.80 --- (1)
4 stickers + 3 beads = 40.80 + 3.10 = 43.90 --- (2)
(1) + (2)
7 stickers + 7 beads = 84.70 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 84.70 ÷ 7 = 12.10 --- (4)
Cost of 1 sticker and 1 bead = $12.10
(b)
4 stickers + 3 beads = 43.90 --- (2)
(4)
x 3 3 stickers + 3 beads = 3 x 12.10 = 36.30 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 43.90 - 36.30
4 stickers - 3 stickers + 3 beads - 3 beads = 7.60
1 sticker = 7.60
Cost of 1 sticker = $7.60
(c)
Substitute 1 sticker = 7.60 into (4).
1 sticker + 1 bead = 12.10
7.60 + 1 bead = 12.10
1 bead = 12.10 - 7.60 = 4.50
Cost of 1 bead = $4.50
Answer(s): (a) $12.10; (b) $7.60; (c) $4.50