1. Solve the following system of equations using the elimination method: 2X-3Y=12 -2X+3Y=12 2. Solve the following system of equations using the Substitution method: 5X-7Y= - 18 4X+3Y=20 3. A total of $80,000 is invested in two funds paying 2.3% and 3.1 % simple interest. The total annual interest is $2000. How much is invested in each fund? 4. Find the point of equilibrium for a system that has a demand equation of p=49-0.0003X and a supply equation of p=33+0.00002X.