Use the order of operations to simplify the expression: 23 + 5 × 10 ÷ 2 – 33 + (11 – 8)

Here you must do mult. and div. BEFORE add'n. and subtr'n.

23 + 5 × 10 ÷ 2 – 33 + (11 – 8)
Mult 5*10, and then div. the result by 2.  Then you will have

23 + 25 - 33 + 3
This simplifies to:  51-33 =   18