If Adam buys 3 beads and 4 stickers, it costs $42.70.
If Adam buys 4 beads and 3 stickers, he will need another $1.40.
- 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 = 42.70 --- (1)
4 beads + 3 stickers = 42.70 + 1.40 = 44.10 --- (2)
(1) + (2)
7 beads + 7 stickers = 86.80 --- (3)
(3)
÷ 7 1 bead + 1 sticker = 86.80 ÷ 7 = 12.40 --- (4)
Cost of 1 bead and 1 sticker = $12.40
(b)
4 beads + 3 stickers = 44.10 --- (2)
(4)
x 3 3 beads + 3 stickers = 3 x 12.40 = 37.20 --- (5)
(2) - (5)
4 beads + 3 stickers - 3 beads - 3 stickers = 44.10 - 37.20
4 beads - 3 beads + 3 stickers - 3 stickers = 6.90
1 bead = 6.90
Cost of 1 bead = $6.90
(c)
Substitute 1 bead = 6.90 into (4).
1 bead + 1 sticker = 12.40
6.90 + 1 sticker = 12.40
1 sticker = 12.40 - 6.90 = 5.50
Cost of 1 sticker = $5.50
Answer(s): (a) $12.40; (b) $6.90; (c) $5.50