sushi emperor Help

Question

Each chef at "Sushi Emperor" prepares 15 regular rolls and 20 vegetarian rolls daily. On Tuesday, each customer ate 2 regular rolls and 3 vegetarian rolls. By the end of the day, 4 regular rolls and 1 vegetarian roll remained uneaten. How many chefs and how many customers were in "Sushi Emperor" on Tuesday?

Answer 1

E = 15R + 20V

C = 2R + 3 V

4R + V left

2 Emperor chefs made 2(15R+20V) = 30R = 40V

13 customers ate 13(2R+3V) = 26R + 39V

leaving 4R + V