[18 + 5(7 – 3)] + 64 ÷ [20 – (8 × 2)]
= [18 + 5 × 4] + 64 ÷ [20 – 16] (Solving simple brackets first)
= [18 + 5 × 4] + 64 ÷ 4 (Solving square brackets)
= [18 + 5 × 4] + 16 (Performing division first)
= [18 + 20] + 16 (Performing multiplication first)
= 38 + 16 (Solving square brackets)
= 54