1. Calculate A from the 1st equation
2. Calculate C from the 2nd equation
3. Plug in these terms into the 3rd equation. Calculate D from this equation.
4. Plug in A and C from the first two equations into equation #4. Plug in D from #3 into this new equation #4 which now contains only the variable A. Calculate A. (28,750,000)
5. Resubstitute this value to calculate D. (3,910,000)
6. Resubstitute these values to calculate C (97,750,000) and B (2,357,500)