p + s = 10000 (1) 0.03p + 0.05s = 380 (2) Let's eliminate p by careful choice of multiplication of (1). Multiply (1) by 0.03: 0.03p + 0.03s = 300 Subtract (2) from (1) 0.03p + 0.03s = 300 -0.03p - 0.05s = -380 --—————————————————————— -0.02s = -80 s = -80/-0.02 = 4000 From (1) p + 4000 = 10000 so p = 6000 — Ans: plus loan was $6000 sallie mae loan was $4000 — Check: 6000(0.03) + 4000(0.05) = 180 + 200 = 380 (ok, interest matches)