Question

(7-5x)(7+5x)+x(25x-9)=4

Answer 1

Ответ: 5.

Решение:

(7 - 5x)(7 + 5x) + x*(25x - 9) = 4

49 - 25x² + 25x² - 9x = 4

49 - 9x = 4

9x = 49 - 4

9x = 45

x = 5