2 stickers and 1 bead cost $9.70.
1 sticker and 2 beads cost $7.10.
- Find the cost of 1 sticker and 1 bead.
- Find the cost of 1 bead.
- Find the cost of 1 sticker.
- Find the cost of 8 stickers and 8 beads.
(a)
2 stickers + 1 bead = 9.70 --- (1)
1 sticker + 2 beads = 7.10 --- (2)
(1) + (2)
3 stickers + 3 beads = 9.70 + 7.10
3 stickers + 3 beads = 16.80 --- (3)
(3)
÷ 3
3 stickers + 3 beads = 16.80
1 sticker + 1 bead = 16.80 ÷ 3
1 sticker + 1 bead = 5.60 --- (4)
Cost of 1 sticker and 1 bead = $5.60
(b)
(2) - (4)
(1 sticker + 2 beads) - (1 sticker + 1 marble) = 7.10 - 5.60
1 sticker - 1 sticker + 2 beads - 1 bead = 1.50
1 bead = 1.50
Cost of 1 bead = $1.50
(c)
Substitute 1 bead = 1.50 into (4).
1 sticker + 1 bead = 5.60
1 sticker + 1.50 = 5.60
1 sticker = 5.60 - 1.50 = 4.10
Cost of 1 sticker = $4.10
(d)
(4)
x 8 1 sticker + 1 bead = 5.60
8 x (1 sticker + 1 marble) = 8 x 5.60
8 stickers + 8 beads = 44.80
Cost of 8 stickers and 8 beads = $44.80
Answer(s): (a) $5.60; (b) $1.50; (c) $4.10; (d) $44.80