how do i write this in equation of this situation

The cost C of a telegram of 18 words is the cost F of the first 10 words plus the cost A of each additional word.

c=f+8a

is it

18=F(10+A)

no, it wouldn't be that

For n words:

C(n)=F if n<=10
C(n)=F+A(n-10) if n>10

To write the equation for the situation described, you can express the total cost C of a telegram with 18 words as the sum of the cost F of the first 10 words and the cost A of each additional word.

The equation can be written as:

C = F + A * (18 - 10)

Let's break this equation down step by step:

1. The cost F of the first 10 words is represented as F.
2. The cost A of each additional word is represented as A.
3. The number of additional words is 18 - 10, which simplifies to 8.
4. Multiply the cost A by the number of additional words to get the total additional cost, represented as A * (18 - 10).
5. Add the cost F of the first 10 words to the total additional cost to find the total cost C.

Therefore, the equation C = F + A * (18 - 10) represents the situation where the cost C of a telegram with 18 words is the cost F of the first 10 words plus the cost A of each additional word.