Question

Решите уравнение 7х^2 + 9х + 2 = 0

Answer 1

D=81-4*2*7=81-56=25=5

х1=-9-5/14=-1

x2=-9+5/14=-4/14=-2/7 

Answer 2

7x₂+9x+2=0

a=7, b=9, c=2

D=b²-4ac

D=9²-4·7·2=81-56=25=5²

$x_{1}=frac{-b+sqrt{D}}{2a} \x_{2}=frac{-b-sqrt{D}}{2a}$

$x_{1}=frac{-9+5}{14}=frac{-4}{14}=-frac{2}{7} \ x_{2}=frac{-9-5}{14}=frac{-14}{14}=-1$

Ответ: $-frac{2}{7}$; -1.