4 stickers and 1 bead cost $21.90.
1 sticker and 4 beads cost $18.60.
- 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 4 stickers and 4 beads.
(a)
4 stickers + 1 bead = 21.90 --- (1)
1 sticker + 4 beads = 18.60 --- (2)
(1) + (2)
5 stickers + 5 beads = 21.90 + 18.60
5 stickers + 5 beads = 40.50 --- (3)
(3)
÷ 55 stickers + 5 beads = 40.50
1 sticker + 1 bead = 40.50 ÷ 5
1 sticker + 1 bead = 8.10 --- (4)
(b)
(2) - (4)
(1 sticker + 4 beads) - (1 sticker + 1 marble) = 18.60 - 8.10
1 sticker - 1 sticker + 4 beads - 1 bead = 10.50
3 beads = 10.50
1 bead = 10.50 ÷ 3 = 3.50
Cost of 1 bead = $3.50
(c)
Substitute 1 bead = 3.50 into (4).
1 sticker + 1 bead = 8.10
1 sticker + 3.50 = 8.10
1 sticker = 8.10 - 3.50 = 4.60
Cost of 1 sticker = $4.60
(d)
(4)
x 4 1 sticker + 1 bead = 8.10
4 x (1 sticker + 1 marble) = 4 x 8.10
4 stickers + 4 beads = 32.40
Cost of 4 stickers and 4 beads = $32.40
Answer(s): (a) $8.10; (b) $3.50; (c) $4.60; (d) $32.40