А) 7⁴⁰ +7³⁸ -2*7³⁹ = 7³⁸ * 7² + 7³⁸ - 2 * 7³⁸ * 7 =
6² * 49¹⁹ 6² * (7²)¹⁹
=7³⁸ (7² + 1 - 2*7) =7² -2 *7 + 1 =(7-1)² = 6² = 1
6² *7³⁸ 6² 6² 6²
б) 36² * 15² = (18²)² * (5*3)² =18⁴ * 5² * 3² = 3² = 9 = 9
18⁴ * 10³ 18⁴ * (5*2)³ 18⁴ * 5³ * 2³ 5 *2³ 5*8 40