2 beads and 1 sticker cost $5.90.
1 bead and 2 stickers cost $4.90.
- 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 7 beads and 7 stickers.
(a)
2 beads + 1 sticker = 5.90 --- (1)
1 bead + 2 stickers = 4.90 --- (2)
(1) + (2)
3 beads + 3 stickers = 5.90 + 4.90
3 beads + 3 stickers = 10.80 --- (3)
(3)
÷ 3
3 beads + 3 stickers = 10.80
1 bead + 1 sticker = 10.80 ÷ 3
1 bead + 1 sticker = 3.60 --- (4)
Cost of 1 bead and 1 sticker = $3.60
(b)
(2) - (4)
(1 bead + 2 stickers) - (1 bead + 1 marble) = 4.90 - 3.60
1 bead - 1 bead + 2 stickers - 1 sticker = 1.30
1 sticker = 1.30
Cost of 1 sticker = $1.30
(c)
Substitute 1 sticker = 1.30 into (4).
1 bead + 1 sticker = 3.60
1 bead + 1.30 = 3.60
1 bead = 3.60 - 1.30 = 2.30
Cost of 1 bead = $2.30
(d)
(4)
x 7 1 bead + 1 sticker = 3.60
7 x (1 bead + 1 marble) = 7 x 3.60
7 beads + 7 stickers = 25.20
Cost of 7 beads and 7 stickers = $25.20
Answer(s): (a) $3.60; (b) $1.30; (c) $2.30; (d) $25.20