As we know, the order of operation of BODMAS is as follows:
Brackets
Of
Division
Multiplication
Addition
Subtraction
15 - (6 + 6 × 6) ÷ (9 + 5)
= 15 – (6 + 36) ÷ (9 + 5)
= 15 - 42 ÷ 14
= 15 - 3
= 12