1) Helga wants to have a lot of helium-filled balloons at her party. • The helium tank costs $58 to rent. • Balloons cost $0.29 each. • She wants to have 5 helium-filled balloons for each party guest. Write an equation that represents the total cost, C, in dollars of the helium-filled balloons for n party guests. Show your work and explain your reasoning why it makes sense.

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answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

300pi

step-by-step explanation: