Answer:

Explanation:
Let m represent number of minutes and e represent number of evenings.
We have been given that most evenings after dinner Duarte spends 30 minutes playing chess with his dad. So after e evenings number of minutes of chess played would be

Since m represents total number of minutes of chess played together, so we will equate 30e to m as:

Therefore, the equation
represents number of minutes, m, that Duarte spent playing chest with his dad if they played chess together, e, evenings.