Question

(5x+2)(-x-4)=0 плиззз срочно,!!!....

Answer 1

(5x+2)(-x-4)=0

-5х^2 - 20x -2x-8=0

-5х^2 - 22x - 8=0

$x_{1,2} = frac{-(-22)+/- sqrt{22^{2}-4*(-5)*(-8) } }{2*(-5)}= frac{22+/- sqrt{484-160} }{-10} = frac{22+/- sqrt{324} }{-10}$=$frac{22+/-18}{-10}$ 

$x_{1} = frac{22+18}{-10} = frac{40}{-10} = -4 </p><p>x_{2} = frac{22-18}{-10} = frac{4}{-10} = -0.4$

Ответ: х1=-4; х2=-0,4