Marina bought 4 notebooks, which cost b dollars each and 3 pens, which cost c dollars each. How much money did Marina spend?

4n+3p

Step-by-step explanation:

You basically multiply both and add them together to get the total sum

i'm sorry but can you put in more details as to what each item costs, if it is just variables then it should be something like b times the amount bought plus c times the amount bought. without the costs i cannot actually give you how much she spent