Adam pays $10.20 for 4 beads and 2 stickers.
A bead costs $2.10 more than 1 sticker.
What is the cost of 2 beads and 3 stickers?
Choose the cheaper item to be 1 u.
1 bead costs $2.10 more than 1 sticker.
The cheaper item is the sticker.

Cost of the sticker = 1 u
Cost of the bead = 1 u + 2.10

Cost of 4 beads = 4 x (1 u + 2.10) = 4 u + 8.40
Cost of 2 stickers = 2 u

Total cost of 4 beads and 2 stickers
= 4 u + 8.40 + 2 u
= 4 u + 2 u + 8.40
= 6 u + 8.40

6 u + 8.40 = 10.20
6 u = 10.20 - 8.40
6 u = 1.80

1 u = 1.80 ÷ 6 = 0.30

Cost of 2 beads and 3 stickers
= 2 x (1 u + 2.10) + 3 u
= 2 u + 4.20 + 3 u
= 2 u + 3 u + 4.20
= 5 u + 4.20
= 5 x 0.30 + 4.20
= 1.50 + 4.20
= $5.70

Answer(s): $5.70