Question

Теңдеуді шеш: 3x2 – 14x – 5 = 0.
Дұрыс жауап саны: 2

Answer 1

$\displaystyle\\3x^2-14x-5=0\\\\D=b^2-4ac=(-14)^2-4*3*(-5)=196+60=256\\\\x_1=\frac{-b+\sqrt{D} }{2a}=\frac{14+\sqrt{256} }{2*3}=\frac{14+16}{6}=\frac{30}{6}=5\\\\ x_2=\frac{-b-\sqrt{D} }{2a}=\frac{14-\sqrt{256} }{2*3}=\frac{14-16}{6}=\frac{-2}{6}=-\frac{1}{3}$

Ответ:  x₁ = 5 ;  x₂ =  $-\frac{1}{3}$