Given:
Total amount of new laptop = $335
Down payment = $50
Number of equal monthly payments = 6
Amount of monthly payments =

To find:
The equation that represents the given situation.
Solution:
We have,
Amount of monthly payments =

Total amount for 6 equal monthly payments =

We know that,
Total amount = Down payment + Total amount of all monthly payments

Therefore, the required equation for the given situation is
.