The sum of twice a number and another number is 24. the difference of twice the first number and the other number is 12. which system would model this situation, and what is the solution? . a.. 2(x + y) = 24. 2(x – y) = 12. solution: (9, 6). b.. 2x + y = 24. 2x – y = 12. solution: (9, 6). c.. 2(x + y) = 24. 2x – y = 12. solution: (6, 9). d.. 2x + y = 24. 2(x – y) = 12. solution: (6, 9)