Question

$\frac{71 ^{3} +49 {}^{3} }{120} + 71 \times 49$
Тиімді тәсілмен есептендер​

Answer 1

(71³ + 49³)/120 + 71•49 =
=(((71³ + 49³) + 71•49•120) / 120 =
= ((71 + 49)(71² - 71•49 + 49²) + 71•49•120)/120=
= (120 • (71² - 71•49 + 49²) + 71•49•120) / 120 =
= 120 • (71² - 71•49 + 49² + 71•49) / 120 =
= 71² - 71•49 + 49² + 71•49 =
= 71² + 49² =
= 5041 + 2401 = 7442