### Instruction: I am going to buy exotic fruits.  Dragonfruit costs $x-4$ dollars.  Starfruit is five dollars less expensive than rambutan.  Rambutan costs $2x$ dollars more than dragonfruit.  How much does it cost to buy one rambutan, two starfruit, and three dragonfruit? Your answer will be an expression that depends on $x$.### Response: To solve this problem, I need to express the prices of all the fruits in terms of $x$ and then add them up according to how many I buy of each.
I already know that dragonfruit costs $x-4$ dollars, so I can use that to find the price of rambutan.
Rambutan costs $2x$ dollars more than dragonfruit, so I can write that as $2x + (x-4) = 3x-4$ dollars.
Starfruit is five dollars less expensive than rambutan, so I can write that as $3x-4 - 5 = 3x-9$ dollars.
Now I have the prices of all the fruits in terms of $x$: dragonfruit is $x-4$, rambutan is $3x-4$, and starfruit is $3x-9$.
To find the total cost of buying one rambutan, two starfruit, and three dragonfruit, I need to multiply each price by the corresponding quantity and add them up.
That gives me $(3x-4) + 2(3x-9) + 3(x-4)$.
To simplify this expression, I can distribute the 2 and the 3 and then combine like terms.
That gives me $3x-4 + 6x-18 + 3x-12$.
Combining like terms, I get $12x-34$.