2 stickers and 1 bead cost $5.70.
1 sticker and 2 beads cost $4.50.
- 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)
2 stickers + 1 bead = 5.70 --- (1)
1 sticker + 2 beads = 4.50 --- (2)
(1) + (2)
3 stickers + 3 beads = 5.70 + 4.50
3 stickers + 3 beads = 10.20 --- (3)
(3)
÷ 3
3 stickers + 3 beads = 10.20
1 sticker + 1 bead = 10.20 ÷ 3
1 sticker + 1 bead = 3.40 --- (4)
Cost of 1 sticker and 1 bead = $3.40
(b)
(2) - (4)
(1 sticker + 2 beads) - (1 sticker + 1 marble) = 4.50 - 3.40
1 sticker - 1 sticker + 2 beads - 1 bead = 1.10
1 bead = 1.10
Cost of 1 bead = $1.10
(c)
Substitute 1 bead = 1.10 into (4).
1 sticker + 1 bead = 3.40
1 sticker + 1.10 = 3.40
1 sticker = 3.40 - 1.10 = 2.30
Cost of 1 sticker = $2.30
(d)
(4)
x 4 1 sticker + 1 bead = 3.40
4 x (1 sticker + 1 marble) = 4 x 3.40
4 stickers + 4 beads = 13.60
Cost of 4 stickers and 4 beads = $13.60
Answer(s): (a) $3.40; (b) $1.10; (c) $2.30; (d) $13.60