Răspuns:
a) [(2² - 3) × 7 + 7²] ÷ 2³
= [(4 - 3) × 7 + 49] ÷ 8
= (1 × 7 + 49) ÷ 8
= (7 + 49) ÷ 8 = 56 ÷ 8 = 7
b) [2.017⁰ + (3²)²⁰ ÷ (3¹³)³]³⁰ ÷ 8²⁰
= (1 + 3⁴⁰ ÷ 3³⁹)³⁰ ÷ 8²⁰
= (1 + 3)²⁰ ÷ 8²⁰
= 4²⁰ ÷ 8²⁰ = (2²)³⁰ ÷ (2³)²⁰
= 2⁶⁰ ÷ 2⁶⁰ = 2⁰ = 1
c) 5 × {5 × [5 × (5² - 3²) - 4²] - 15²} ÷ 19 - 5²
= 5 × {5 × [5 × (25 - 9) - 16] - 225} ÷ 19 - 25
= 5 × [5 × (5 × 16 - 16) - 225] ÷ 19 - 25
= 5 × [5 × (80 - 16) - 225] ÷ 19 - 25
= 5 × (5 × 64 - 225) ÷ 19 - 25
= 5 × (320 - 225) ÷ 19 - 25
= 5 × 95 ÷ 19 - 25
= 475 ÷ 19 - 25 = 25 - 25 = 0