Let S₁ and S₂ , V₂ and V₁, t₁ and t₂, respectively, distance, speed and time on the first and second parts of the path. \r\n\r\pogda average speed all the way:\r\n\r\n( S₁ + S₂) / (t₁ + t₂) = (S₁ + S₂) / (S₁ / V₁ + S₂ / V₂) = 56.\r\n\r\puwede new symbols: x = V₁ = S₂, y = V₂ = S₁ in accordance with the requirement of numerical equality. The result is the equation\r\n\r\n(y + x) / (y / x + x / y) = 56, after conversion \r\n\r\n(56 – y)x2 - у2х + 56у2 = 0.\r\n\r\imeem quadratic equation with two unknown integer values. \r\n\r\povodom in the equation y = 50, we find the root x = 350. \r\n\r\vicissim you visit, \r\n\r\n50/350 + 350/50 = 1/7 + 7 (hours).\r\n\r\proverka: 400/(1/7 + 7) = 56 (km).

177

Answer add

### Other questions in the section - different_topics

Drelann

How to answer the question why do you dance?, options?

2019-02-27 02:28:58

Seoz

How did the expression “white bone and blue blood”?

2019-02-27 02:28:40

Valentina

What is the use to find a large number of cells under the eggs?

2019-02-27 02:28:24

Aleksandr

What filters required for a pond or small pond?

2019-02-27 02:27:25

Saizar

What happened to Georgy Danelia 24.02.2019 year? G. Danelia in the NICU?

2019-02-27 02:27:23