5 beads and 1 sticker cost $16.90.
1 bead and 5 stickers cost $26.90.
- 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 = 16.90 --- (1)
1 bead + 5 stickers = 26.90 --- (2)
(1) + (2)
6 beads + 6 stickers = 16.90 + 26.90
6 beads + 6 stickers = 43.80 --- (3)
(3)
÷ 66 beads + 6 stickers = 43.80
1 bead + 1 sticker = 43.80 ÷ 6
1 bead + 1 sticker = 7.30 --- (4)
(b)
(2) - (4)
(1 bead + 5 stickers) - (1 bead + 1 marble) = 26.90 - 7.30
1 bead - 1 bead + 5 stickers - 1 sticker = 19.60
4 stickers = 19.60
1 sticker = 19.60 ÷ 4 = 4.90
Cost of 1 sticker = $4.90
(c)
Substitute 1 sticker = 4.90 into (4).
1 bead + 1 sticker = 7.30
1 bead + 4.90 = 7.30
1 bead = 7.30 - 4.90 = 2.40
Cost of 1 bead = $2.40
(d)
(4)
x 9 1 bead + 1 sticker = 7.30
9 x (1 bead + 1 marble) = 9 x 7.30
9 beads + 9 stickers = 65.70
Cost of 9 beads and 9 stickers = $65.70
Answer(s): (a) $7.30; (b) $4.90; (c) $2.40; (d) $65.70