Question

28-[15-{8+20÷(7-8-6)}]​

Answer 1

Step-by-step explanation:

$28 - (15 - (8 + 20 \div (7 - 8 - 6))) \\ \\ = 28 - (15 - (8 + 20 \div ( - 7))) \\ \\ = 28 - (15 - (28 \div ( - 7))) \\ \\ = 28 - (15 - ( - 4)) \\ \\ = 28 - ( 15 +4) \\ \\ = 28 - (19) \\ \\ = 28 - 19 \\ \\ = 9$