Question

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 $x$.

Answer 1

We can represent the Rambutan as x-4+2x or 3x-4 because it costs 2x dollars more than the Dragonfruit. 

We can represent the Starfruit as 3x-4-5 or 3x-9 because it costs 5 dollars less than the Rambutan

Therefore the overall equation would be:
(3x-4)+2(3x-9)+3(x-4) (distribute)
3x-4+6x-18+3x-12 (combine like terms)
12x-34 

Hope this helps