Question

Помогите с номером 1

Answer 1

(3a - 4)² = (3a)² - 2 * 3a * 4 + 4² = 9a² - 24a + 16

(x + 5y)² = x² + 2 * x * 5y + (5y)² = x² + 10xy + 25y²

$(x - 1 \frac{2}{3}y )(x + 1 \frac{2}{3}y) = x ^{2} - (1 \frac{2}{3}y) ^{2} = x^{2} -( \frac{5}{3}y) ^{2}= x^{2} - \frac{25}{9} y^{2}=$$x^{2} -2 \frac{7}{9} y^{2}$