{18 × [(5 + 15) ÷ 4] + 25} × 12 + 16 × 3
Do : 5 + 15 = 20
= {18 × [20 ÷ 4] + 25} × 12 + 16 × 3
Do: 20 ÷ 4 = 5
= {18 × 5 + 25} × 12 + 16 × 3
Do: 18 x 5 = 90
= {90 + 25} × 12 + 16 × 3
Do: 90 + 25 = 115
= 115 × 12 + 16 × 3
Do: 115 x 12 = 1380
= 1380 + 16 × 3
Do: 16 x 3 = 48
= 1380 + 48
Do: 1380 + 48
= 1428
Answer: 1428