(28*89)+899-12(13*15)

Compute step by step:

• 28 × 89 = 2492
• 13 × 15 = 195
• 12 × (13 × 15) = 12 × 195 = 2340

Then: 2492 + 899 − 2340 = 3391 − 2340 = 1051

Answer: 1051