@sleepyjess The function c(x) = 3x − 4 determines how many cupcakes need to be purchased for a birthday party, where x is the number of kids at the party. The party planner uses d(c(x)) to find the amount of money to bring for the cupcake purchase. The function d(x) = 2x + 5. Solve for how much money to bring when there are 7 kids at the party.

Question

sleepyjess · Answer

First, do you know what d(c(x)) means?

here_to_help15 · Answer

We have two individual functions.

here_to_help15 · Answer

c(x)=3x-4, how many cupcakes to bring.

gabylovesyou · Answer

yes it means d(3*7 - 4) = 2*(3*7 - 4) + 5

sleepyjess · Answer

Yep :(

sleepyjess · Answer

*:)

gabylovesyou · Answer

but i keep solving it wrong ._.

here_to_help15 · Answer

d(x)=2x+5, how much money for a certain number of cupcakes.

sleepyjess · Answer

Ok, your substituting looks good.

sleepyjess · Answer

So do you know where you keep going wrong?

gabylovesyou · Answer

no idea... first i start with the parenthesis right ?

here_to_help15 · Answer

To determine how much money the party planner needs means that they use the function
d(c(x)) like @sleepyjess said

sleepyjess · Answer

Yep, start with 3*7  in the parentheses

gabylovesyou · Answer

Nvm i got it lol its 39

here_to_help15 · Answer

Which is,d(3*7 - 4) = 2*(3*7 - 4) + 5 as you said

here_to_help15 · Answer

Sorry if i wasnt much help hehe cya :P :)

gabylovesyou · Answer

Thank you both :)

sleepyjess · Answer

Yep, 39 is correct :) No problem!

here_to_help15 · Answer

Np : )

here_to_help15 · Answer

hehe ill take ur thank you as my medal :)

sleepyjess · Answer

Wow this was my 2000th question answered!