2 stickers and 1 bead cost $12.70.
1 sticker and 2 beads cost $12.20.
- 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 = 12.70 --- (1)
1 sticker + 2 beads = 12.20 --- (2)
(1) + (2)
3 stickers + 3 beads = 12.70 + 12.20
3 stickers + 3 beads = 24.90 --- (3)
(3)
÷ 3
3 stickers + 3 beads = 24.90
1 sticker + 1 bead = 24.90 ÷ 3
1 sticker + 1 bead = 8.30 --- (4)
Cost of 1 sticker and 1 bead = $8.30
(b)
(2) - (4)
(1 sticker + 2 beads) - (1 sticker + 1 marble) = 12.20 - 8.30
1 sticker - 1 sticker + 2 beads - 1 bead = 3.90
1 bead = 3.90
Cost of 1 bead = $3.90
(c)
Substitute 1 bead = 3.90 into (4).
1 sticker + 1 bead = 8.30
1 sticker + 3.90 = 8.30
1 sticker = 8.30 - 3.90 = 4.40
Cost of 1 sticker = $4.40
(d)
(4)
x 8 1 sticker + 1 bead = 8.30
8 x (1 sticker + 1 marble) = 8 x 8.30
8 stickers + 8 beads = 66.40
Cost of 8 stickers and 8 beads = $66.40
Answer(s): (a) $8.30; (b) $3.90; (c) $4.40; (d) $66.40