We must use the correct order we know as pemdas.
25 + 15 = 40
{18 * [40 ÷ 4] + 25] * 12 + 16 * 3
40 ÷ 4 = 10
{18 * 10 + 25} * 12 + 16 * 3
18 * 10 = 180
{180 + 25} * 12 + 16 * 3
180 + 25 = 205
205 * 12 + 16 * 3
205 * 12 = 2460
2460 + 16 * 3
16 * 3 = 48
2460 + 48 = 2508
So, the answer is 2508