If Adam buys 4 beads and 5 marbles, it costs $48.10.
If Adam buys 5 beads and 4 marbles, he will need another $4.60.
- Find the cost of 1 bead and 1 marble.
- Find the cost of 1 bead.
- Find the cost of 1 marble.
(a)
4 beads + 5 marbles = 48.10 --- (1)
5 beads + 4 marbles = 48.10 + 4.60 = 52.70 --- (2)
(1) + (2)
9 beads + 9 marbles = 100.80 --- (3)
(3)
÷ 9 1 bead + 1 marble = 100.80 ÷ 9 = 11.20 --- (4)
Cost of 1 bead and 1 marble = $11.20
(b)
5 beads + 4 marbles = 52.70 --- (2)
(4)
x 4 4 beads + 4 marbles = 4 x 11.20 = 44.80 --- (5)
(2) - (5)
5 beads + 4 marbles - 4 beads - 4 marbles = 52.70 - 44.80
5 beads - 4 beads + 4 marbles - 4 marbles = 7.90
1 bead = 7.90
Cost of 1 bead = $7.90
(c)
Substitute 1 bead = 7.90 into (4).
1 bead + 1 marble = 11.20
7.90 + 1 marble = 11.20
1 marble = 11.20 - 7.90 = 3.30
Cost of 1 marble = $3.30
Answer(s): (a) $11.20; (b) $7.90; (c) $3.30