Answer:
The cost of one trinket is $4 and the cost of one doodads is $7.
Explanation:
Let x represents the cost of one trinket and y represents the cost of one doodads,
Since, $ 30 to make 4 trinkets and 2 doodads,
⇒ 4x + 2y = 30 ------- (1),
Also, $ 40 to make 3 trinkets and 4 doodads,
⇒ 3x + 4y = 40 ------- (2),
Equation (2) - 2 × Equation (1),
We get,
-5x = - 20
⇒ x = 4
From equation (1),
16 + 2y = 30
⇒ 2y = 14
⇒ y = 7
Hence, the cost of one trinket is $ 4 and the cost of one doodads is $ 7.