Question

4x⁻²+9x⁻¹+5=0 решите уравнение

Answer 1

......................

Answer 2

Ответ:

Х1 = -1

Х2 = -0,8 ИЛИ

$- \frac{4}{5}$

Объяснение:

${4x}^{ - 2} + {9 x}^{ - 1} + 5 = 0 \\ t = {x}^{ - 1} \\ {4t}^{2} + 9t + 5 = 0 \\ {4t}^{2} + 4t + 5t + 5 = 0 \\ 4t \times (t + 1) + 5 \times (t + 1) = 0 \\ (t + 1)(4t + 5) = 0$

$t + 1 = 0 \\ t = - 1 \\ {x}^{ - 1} = - 1 \\ x = - 1$

$4t + 5 = 0 \\ 4t = - 5 \\ t = - \frac{5}{4} \\ {x}^{ - 1} = - \frac{5}{4} \\ x = - \frac{4}{5}$