If Adam buys 3 stickers and 4 beads, it costs $38.70.
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 = 38.70 --- (1)
4 stickers + 3 beads = 38.70 + 3.10 = 41.80 --- (2)
(1) + (2)
7 stickers + 7 beads = 80.50 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 80.50 ÷ 7 = 11.50 --- (4)
Cost of 1 sticker and 1 bead = $11.50
(b)
4 stickers + 3 beads = 41.80 --- (2)
(4)
x 3 3 stickers + 3 beads = 3 x 11.50 = 34.50 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 41.80 - 34.50
4 stickers - 3 stickers + 3 beads - 3 beads = 7.30
1 sticker = 7.30
Cost of 1 sticker = $7.30
(c)
Substitute 1 sticker = 7.30 into (4).
1 sticker + 1 bead = 11.50
7.30 + 1 bead = 11.50
1 bead = 11.50 - 7.30 = 4.20
Cost of 1 bead = $4.20
Answer(s): (a) $11.50; (b) $7.30; (c) $4.20