Question

7x²+9x=0 am nevoie urgent!​

Answer 1

Răspuns:

Explicație pas cu pas:

7$x^{2}$+9x=0

a=7

b=9

c=0

• D=$b^{2}$-4ac= $9^{2}$-4*7*0= 81-0=81>0

$x_{1}$=$\frac{-b+\sqrt{D} }{2*a}=$$\frac{-9+\sqrt{81} }{2*7}=$$\frac{-9+9}{14}=$$\frac{0}{14}=$0

$x_{2}$=$\frac{-b-\sqrt{D} }{2*a}=$$\frac{-9-\sqrt{81} }{2*7}=$$\frac{-9-9}{14}=$$\frac{-18}{14}/_{:2} =$$\frac{-9}{7}$

S.f.= {0; $\frac{-9}{7}$}