John is starting a t-shirt business. He has an initial startup cost of $900. Each t-shirt costs $20 to produce and he plans to sell them for $30. How many sweatshirts must John sell before he starts to make a profit? 1. Write 2 equations using Y as the cost in dollars and X as the number of t-shirts.
2. Solve the system algebraically.
3. Solve the system graphically.