Question

Формулы сокращеного умножения:
1)
$(2a - b) {}^{3}$

2)
$125t {}^{3} - 27b {}^{3}$

Answer 1

1). $(2a - b) {}^{3} = \(2a {)}^{3} - 3 times (2a {)}^{2} times b + \ + 3 times 2a {b}^{2} - {b}^{3} = \ 8 {a}^{3} - 12 {a}^{2} b + 6a {b}^{2} - {b}^{3} .$
2). $125t {}^{3} - 27b {}^{3} = (5t {)}^{3} - (3b {)}^{3} = \(5t - 3b) times (25 {t}^{2} - 15tb + 9 {b}^{2} ) : .$