Adam pays $11.80 for 2 beads and 4 stickers.
A bead costs $2.30 more than 1 sticker.
What is the cost of 3 beads and 4 stickers?
Choose the cheaper item to be 1 u.
1 bead costs $2.30 more than 1 sticker.
The cheaper item is the sticker.

Cost of the sticker = 1 u
Cost of the bead = 1 u + 2.30

Cost of 2 beads = 2 x (1 u + 2.30) = 2 u + 4.60
Cost of 4 stickers = 4 u

Total cost of 2 beads and 4 stickers
= 2 u + 4.60 + 4 u
= 2 u + 4 u + 4.60
= 6 u + 4.60

6 u + 4.60 = 11.80
6 u = 11.80 - 4.60
6 u = 7.20

1 u = 7.20 ÷ 6 = 1.20

Cost of 3 beads and 4 stickers
= 3 x (1 u + 2.30) + 4 u
= 3 u + 6.90 + 4 u
= 3 u + 4 u + 6.90
= 7 u + 6.90
= 7 x 1.20 + 6.90
= 8.40 + 6.90
= $15.30

Answer(s): $15.30