If Adam buys 4 beads and 5 marbles, it costs $68.20.
If Adam buys 5 beads and 4 marbles, he will have $50 left.
- 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 = 68.20 --- (1)
5 beads + 4 marbles = 68.20 - 50 = 63.20 --- (2)
(1) + (2)
9 beads + 9 marbles = 131.40 --- (3)
(3)
÷ 9 1 bead + 1 marble = 131.40 ÷ 9 = 14.60 --- (4)
Cost of 1 bead and 1 marble = $14.60
(b)
(4)
x 4 4 beads + 4 marbles = 4 x 14.60 = 58.40 --- (5)
(2) - (5)
5 beads + 4 marbles - 4 beads - 4 marbles = 63.20 - 58.40
5 beads - 4 beads - 4 marbles + 4 marbles = 4.80
1 bead = 4.80
Cost of 1 bead = $4.80
(c)
Substitute 1 bead = 4.80 into (4).
1 bead + 1 marble = 14.60
4.80 + 1 marble = 14.60
1 marble = 14.60 - 4.80 = 9.80
Cost of 1 marble = $9.80
Answer(s): (a) $14.60; (b) $4.80; (c) $9.80