Here is your question:
Write an expression for 78 divided by d
To make an expression, or equation, you can simplify the question.
78 is just 78. Here is the beginning of your expression:
Divided by is a phrase that means "to divide". That means you'll be dividing in your equation, so you need to add the division sign to your expression. Here is your current expression:
A number d can be any number. A number d can be written as just d. After you add that, this will be your current equation:
You have your expression. In the question, for dividing, you need to use /. You can just replace the division sign with a /.
Your answer is 78/d