Можно хотяб 3 Пж во да

1) 1 - 5x² = 1 - 5 * (- 4)² = 1 - 5 * 16 = - 79

2) y⁷ * y¹² = y⁷⁺¹² = y¹⁹

y²⁰ : y⁵ = y²⁰⁻⁵ = y¹⁵

(y²)⁸ = y¹⁶

( 2y)⁴ = 16y⁴

a) - 2ab³ * 3a² * b⁴ = - 6a¹⁺²b³⁺⁴ = - 6a³b⁷

б) (-2a⁵b²)³ = - 8a¹⁵b⁶

$\frac{25^{2}*5^{5}}{5^{7} } =\frac{(5^{2})^{2}*5^{5}}{5^{7} } =\frac{5^{4}* 5^{5} }{5^{7} }=5^{4+5-7} =5^{2} =25$