If Adam buys 4 stickers and 5 beads, it costs $540.
If Adam buys 5 stickers and 4 beads, he will need another $0.90.
- Find the cost of 1 sticker and 1 bead.
- Find the cost of 1 sticker.
- Find the cost of 1 bead.
(a)
4 stickers + 5 beads = 540 --- (1)
5 stickers + 4 beads = 540 + 0.90 = 54.90 --- (2)
(1) + (2)
9 stickers + 9 beads = 108.90 --- (3)
(3)
÷ 9 1 sticker + 1 bead = 108.90 ÷ 9 = 12.10 --- (4)
Cost of 1 sticker and 1 bead = $12.10
(b)
5 stickers + 4 beads = 54.90 --- (2)
(4)
x 4 4 stickers + 4 beads = 4 x 12.10 = 48.40 --- (5)
(2) - (5)
5 stickers + 4 beads - 4 stickers - 4 beads = 54.90 - 48.40
5 stickers - 4 stickers + 4 beads - 4 beads = 6.50
1 sticker = 6.50
Cost of 1 sticker = $6.50
(c)
Substitute 1 sticker = 6.50 into (4).
1 sticker + 1 bead = 12.10
6.50 + 1 bead = 12.10
1 bead = 12.10 - 6.50 = 5.60
Cost of 1 bead = $5.60
Answer(s): (a) $12.10; (b) $6.50; (c) $5.60