Question

помогите плиз
буду благодарен​

Answer 1

a³ + b³ = (a + b)(a² - ab + b²)

(a - b)² = a² - 2ab + b²

(71³ + 49³)/120 - 71*49 = (71 + 49)*(71² - 71*49 + 49²)/120 - 71*49 = 120*(71² - 71*49 + 49²)/120 - 71*49 =  71² - 2*71*49 + 49² = (71 - 49)² = 22² = 484