3m-2n-5, m+2n=15;

Interpret the problem as the system:

• 3m − 2n = 5
• m + 2n = 15

Solve by elimination:

• Add the equations: (3m − 2n) + (m + 2n) = 5 + 15 → 4m = 20 → m = 5
• Substitute into m + 2n = 15: 5 + 2n = 15 → 2n = 10 → n = 5

Check: 3(5) − 2(5) = 15 − 10 = 5 ✓

Solution: m = 5, n = 5.