Question

⁻2x²+7x=9 решите уравнение

Answer 1

-2x²+7x=9

-2x² + 7x -9 = 0

 

Д = b² - 4ac = 7² - 4×(-2)×9 = 49 + 72 = √121 = 11

 

x1 = -7 + 11/2×(-2) = 4/-4 = -1

x2 = -7 - 11/2×(-2) = -18/-4 = 4.5

 

Ответ: -1, 4.5