2 beads and 1 sticker cost $8.20.
1 bead and 2 stickers cost $9.20.
- 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 = 8.20 --- (1)
1 bead + 2 stickers = 9.20 --- (2)
(1) + (2)
3 beads + 3 stickers = 8.20 + 9.20
3 beads + 3 stickers = 17.40 --- (3)
(3)
÷ 3
3 beads + 3 stickers = 17.40
1 bead + 1 sticker = 17.40 ÷ 3
1 bead + 1 sticker = 5.80 --- (4)
Cost of 1 bead and 1 sticker = $5.80
(b)
(2) - (4)
(1 bead + 2 stickers) - (1 bead + 1 marble) = 9.20 - 5.80
1 bead - 1 bead + 2 stickers - 1 sticker = 3.40
1 sticker = 3.40
Cost of 1 sticker = $3.40
(c)
Substitute 1 sticker = 3.40 into (4).
1 bead + 1 sticker = 5.80
1 bead + 3.40 = 5.80
1 bead = 5.80 - 3.40 = 2.40
Cost of 1 bead = $2.40
(d)
(4)
x 7 1 bead + 1 sticker = 5.80
7 x (1 bead + 1 marble) = 7 x 5.80
7 beads + 7 stickers = 40.60
Cost of 7 beads and 7 stickers = $40.60
Answer(s): (a) $5.80; (b) $3.40; (c) $2.40; (d) $40.60