Question

как решить уравнение 18/х=9-х

Answer 1

18х = 9 -х
18 = 9х - x^2
x^2 -9x + 18 = 0
x1 + x2 = 9
x1*x2 = 18

x1 = 6
x2 = 3

ОДЗ x != 0

Answer 2

$frac{18}{x} =9-x/*x neq 0 \ 18=9x- x^{2} \ 9x- x^{2} =18 \ D=81-72=9 \ sqrt{D} =3 \ x_{1} = frac{-9+3}{-2} = frac{-6}{-2} =3 \ x_{1} = frac{-9-3}{-2} = frac{-12}{-2} =6$