If Adam buys 3 beads and 4 stickers, it costs $36.90.
If Adam buys 4 beads and 3 stickers, he will need another $2.50.
- Find the cost of 1 bead and 1 sticker.
- Find the cost of 1 bead.
- Find the cost of 1 sticker.
(a)
3 beads + 4 stickers = 36.90 --- (1)
4 beads + 3 stickers = 36.90 + 2.50 = 39.40 --- (2)
(1) + (2)
7 beads + 7 stickers = 76.30 --- (3)
(3)
÷ 7 1 bead + 1 sticker = 76.30 ÷ 7 = 10.90 --- (4)
Cost of 1 bead and 1 sticker = $10.90
(b)
4 beads + 3 stickers = 39.40 --- (2)
(4)
x 3 3 beads + 3 stickers = 3 x 10.90 = 32.70 --- (5)
(2) - (5)
4 beads + 3 stickers - 3 beads - 3 stickers = 39.40 - 32.70
4 beads - 3 beads + 3 stickers - 3 stickers = 6.70
1 bead = 6.70
Cost of 1 bead = $6.70
(c)
Substitute 1 bead = 6.70 into (4).
1 bead + 1 sticker = 10.90
6.70 + 1 sticker = 10.90
1 sticker = 10.90 - 6.70 = 4.20
Cost of 1 sticker = $4.20
Answer(s): (a) $10.90; (b) $6.70; (c) $4.20