Answer :

Look at the pic. It explains it.
View image Ilovetohelp
[tex]4\ tomatoes\ :\ 3.40\ dollars[/tex]

Divide each side by 4 (division property of equality lets us do this) to find the price of one tomato.

[tex]1\ tomato\ :\ \boxed{0.85\ dollars}[/tex] (85 cents)