5 stickers and 1 bead cost $23.30.
1 sticker and 5 beads cost $22.90.
- 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)
5 stickers + 1 bead = 23.30 --- (1)
1 sticker + 5 beads = 22.90 --- (2)
(1) + (2)
6 stickers + 6 beads = 23.30 + 22.90
6 stickers + 6 beads = 46.20 --- (3)
(3)
÷ 66 stickers + 6 beads = 46.20
1 sticker + 1 bead = 46.20 ÷ 6
1 sticker + 1 bead = 7.70 --- (4)
(b)
(2) - (4)
(1 sticker + 5 beads) - (1 sticker + 1 marble) = 22.90 - 7.70
1 sticker - 1 sticker + 5 beads - 1 bead = 15.20
4 beads = 15.20
1 bead = 15.20 ÷ 4 = 3.80
Cost of 1 bead = $3.80
(c)
Substitute 1 bead = 3.80 into (4).
1 sticker + 1 bead = 7.70
1 sticker + 3.80 = 7.70
1 sticker = 7.70 - 3.80 = 3.90
Cost of 1 sticker = $3.90
(d)
(4)
x 4 1 sticker + 1 bead = 7.70
4 x (1 sticker + 1 marble) = 4 x 7.70
4 stickers + 4 beads = 30.80
Cost of 4 stickers and 4 beads = $30.80
Answer(s): (a) $7.70; (b) $3.80; (c) $3.90; (d) $30.80