Adam pays $8.20 for 2 beads and 4 stickers.
A bead costs $2.90 more than 1 sticker.
What is the cost of 4 beads and 3 stickers?
Choose the cheaper item to be 1 u.
1 bead costs $2.90 more than 1 sticker.
The cheaper item is the sticker.

Cost of the sticker = 1 u
Cost of the bead = 1 u + 2.90

Cost of 2 beads = 2 x (1 u + 2.90) = 2 u + 5.80
Cost of 4 stickers = 4 u

Total cost of 2 beads and 4 stickers
= 2 u + 5.80 + 4 u
= 2 u + 4 u + 5.80
= 6 u + 5.80

6 u + 5.80 = 8.20
6 u = 8.20 - 5.80
6 u = 2.40

1 u = 2.40 ÷ 6 = 0.40

Cost of 4 beads and 3 stickers
= 4 x (1 u + 2.90) + 3 u
= 4 u + 11.60 + 3 u
= 4 u + 3 u + 11.60
= 7 u + 11.60
= 7 x 0.40 + 11.60
= 2.80 + 11.60
= $14.40

Answer(s): $14.40