If Adam buys 3 stickers and 4 beads, it costs $39.70.
If Adam buys 4 stickers and 3 beads, he will need another $1.80.
- 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 = 39.70 --- (1)
4 stickers + 3 beads = 39.70 + 1.80 = 41.50 --- (2)
(1) + (2)
7 stickers + 7 beads = 81.20 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 81.20 ÷ 7 = 11.60 --- (4)
Cost of 1 sticker and 1 bead = $11.60
(b)
4 stickers + 3 beads = 41.50 --- (2)
(4)
x 3 3 stickers + 3 beads = 3 x 11.60 = 34.80 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 41.50 - 34.80
4 stickers - 3 stickers + 3 beads - 3 beads = 6.70
1 sticker = 6.70
Cost of 1 sticker = $6.70
(c)
Substitute 1 sticker = 6.70 into (4).
1 sticker + 1 bead = 11.60
6.70 + 1 bead = 11.60
1 bead = 11.60 - 6.70 = 4.90
Cost of 1 bead = $4.90
Answer(s): (a) $11.60; (b) $6.70; (c) $4.90