5 beads and 1 sticker cost $8.80.
1 bead and 5 stickers cost $12.80.
- Find the cost of 1 bead and 1 sticker.
- Find the cost of 1 sticker.
- Find the cost of 1 bead.
- Find the cost of 9 beads and 9 stickers.
(a)
5 beads + 1 sticker = 8.80 --- (1)
1 bead + 5 stickers = 12.80 --- (2)
(1) + (2)
6 beads + 6 stickers = 8.80 + 12.80
6 beads + 6 stickers = 21.60 --- (3)
(3)
÷ 66 beads + 6 stickers = 21.60
1 bead + 1 sticker = 21.60 ÷ 6
1 bead + 1 sticker = 3.60 --- (4)
(b)
(2) - (4)
(1 bead + 5 stickers) - (1 bead + 1 marble) = 12.80 - 3.60
1 bead - 1 bead + 5 stickers - 1 sticker = 9.20
4 stickers = 9.20
1 sticker = 9.20 ÷ 4 = 2.30
Cost of 1 sticker = $2.30
(c)
Substitute 1 sticker = 2.30 into (4).
1 bead + 1 sticker = 3.60
1 bead + 2.30 = 3.60
1 bead = 3.60 - 2.30 = 1.30
Cost of 1 bead = $1.30
(d)
(4)
x 9 1 bead + 1 sticker = 3.60
9 x (1 bead + 1 marble) = 9 x 3.60
9 beads + 9 stickers = 32.40
Cost of 9 beads and 9 stickers = $32.40
Answer(s): (a) $3.60; (b) $2.30; (c) $1.30; (d) $32.40