If Adam buys 4 stickers and 5 beads, it costs $54.80.
If Adam buys 5 stickers and 4 beads, he will need another $2.90.
- 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 = 54.80 --- (1)
5 stickers + 4 beads = 54.80 + 2.90 = 57.70 --- (2)
(1) + (2)
9 stickers + 9 beads = 112.50 --- (3)
(3)
÷ 9 1 sticker + 1 bead = 112.50 ÷ 9 = 12.50 --- (4)
Cost of 1 sticker and 1 bead = $12.50
(b)
5 stickers + 4 beads = 57.70 --- (2)
(4)
x 4 4 stickers + 4 beads = 4 x 12.50 = 500 --- (5)
(2) - (5)
5 stickers + 4 beads - 4 stickers - 4 beads = 57.70 - 500
5 stickers - 4 stickers + 4 beads - 4 beads = 7.70
1 sticker = 7.70
Cost of 1 sticker = $7.70
(c)
Substitute 1 sticker = 7.70 into (4).
1 sticker + 1 bead = 12.50
7.70 + 1 bead = 12.50
1 bead = 12.50 - 7.70 = 4.80
Cost of 1 bead = $4.80
Answer(s): (a) $12.50; (b) $7.70; (c) $4.80