if one year to a person is like seven years to a dog, and one day to a person is like one week to a dog, then a dog can have 21 meals everyday.

how do you write an equation relating the data in this situation?

by equation i mean a linear equation

To write an equation relating the data in this situation, we need to consider the ratios given. Let's break down the information:

1. "One year to a person is like seven years to a dog": This means that the ratio of dog years to human years is 7:1. In other words, for every one year a person ages, a dog ages seven years.

2. "One day to a person is like one week to a dog": This means that the ratio of dog days to human days is 1:7. For every one day that passes for a person, a dog experiences one week.

Now, let's denote:

- D = Dog's age in dog years
- H = Person's age in human years
- DD = Dog's age in dog days
- HD = Person's age in human days

Based on the given information, we can establish the following equations:

1. Dog's age in dog years (D) = 7 * Person's age in human years (H)
D = 7H

2. Dog's age in dog days (DD) = 7 * Person's age in human days (HD)
DD = 7HD

Now, we can use these equations to find the number of meals a dog can have every day:

Since dogs can have 21 meals every day, we can set up the following equation:

Number of dog meals per day = Dog's age in dog days / 7
= DD / 7

Substituting DD with 7HD, we get:
Number of dog meals per day = (7HD) / 7
= HD

Therefore, the equation in this situation is Number of dog meals per day = HD.