A large cheese pizza at Peter’s Pizzeria costs $6.80 plus $0.90 for each topping. The cost of a large cheese pizza at Gavin’s Pizzeria is $7.30 plus $0.65 for each topping. How many toppings need to be added to a large cheese pizza from Peter’s Pizzeria and Gavin’s Pizzeria in order for the pizzas to cost the same, not including tax?
Let's represent the number of toppings added as T.
The cost of a large cheese pizza at Peter’s Pizzeria is 6.8 + 0.9T.
The cost of a large cheese pizza at Gavin’s Pizzeria is 7.3 + 0.65T.
To find the number of toppings needed for the pizzas to cost the same, we set the two equations equal to each other:
6.8 + 0.9T = 7.3 + 0.65T
Subtract 0.65T from both sides:
6.8 + 0.25T = 7.3
Subtract 6.8 from both sides:
0.25T = 0.5
Divide both sides by 0.25:
T = 2
Thus, 2 toppings need to be added to a large cheese pizza from Peter’s Pizzeria and Gavin’s Pizzeria to have the same cost. Answer: \boxed{2}.