4 beads and 1 sticker cost $20.20.
1 bead and 4 stickers cost $10.30.
- 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)
4 beads + 1 sticker = 20.20 --- (1)
1 bead + 4 stickers = 10.30 --- (2)
(1) + (2)
5 beads + 5 stickers = 20.20 + 10.30
5 beads + 5 stickers = 30.50 --- (3)
(3)
÷ 55 beads + 5 stickers = 30.50
1 bead + 1 sticker = 30.50 ÷ 5
1 bead + 1 sticker = 6.10 --- (4)
(b)
(2) - (4)
(1 bead + 4 stickers) - (1 bead + 1 marble) = 10.30 - 6.10
1 bead - 1 bead + 4 stickers - 1 sticker = 4.20
3 stickers = 4.20
1 sticker = 4.20 ÷ 3 = 1.40
Cost of 1 sticker = $1.40
(c)
Substitute 1 sticker = 1.40 into (4).
1 bead + 1 sticker = 6.10
1 bead + 1.40 = 6.10
1 bead = 6.10 - 1.40 = 4.70
Cost of 1 bead = $4.70
(d)
(4)
x 7 1 bead + 1 sticker = 6.10
7 x (1 bead + 1 marble) = 7 x 6.10
7 beads + 7 stickers = 42.70
Cost of 7 beads and 7 stickers = $42.70
Answer(s): (a) $6.10; (b) $1.40; (c) $4.70; (d) $42.70