Question

VA ROG FRUMOS SA MA AJUTATI!!!
IMI TREBUIE URGENT!!!
MULTUMESC

Answer 1

Răspuns:

1. $x^{2}$-9=(x-3)(x+3)

2. $x^{2}$+6x=0

   x(x+6)=0 => $x_{1}$=0

                       x+6=0, $x_{2}$=-6

3. $x^{2}$-0,04=0 =>

4. $x^{2}$-2x+1=0

   a=1, b=-2, c=1, Δ=4-4=0

   $x_{1,2}$ = $\frac{-b}{2a}=\frac{2}{2}=1$

5. $x^{2}$-1=0 =>

6. $x^{2}$-3x+2=0

   a=1, b= -3, c=2, Δ=9-8=1

   $x_{1}$=$\frac{3+1}{2} = \frac{4}{2} = 2$

   $x_{2} = \frac{3-1}{2} = \frac{2}{2} = 1$

7. $x^{2}$=0 => x=0

8. 5$x^{2}$+7x=0

   x(5x+7)=0 => $x_{1}$=0

                         5x+7=0, 5x=-7 => $x= -\frac{7}{5}$

9. $-x^{2}$=-2 | *(-1) => $x^{2}$=2 => x=$\sqrt{2}$

10. $x^{2}$+6x+9=0

    a=1, b=6, c=9, Δ=36-36=0

    $x_{1,2}$ = $\frac{-6}{2}$= -3

11. $x^{2}$=-8 | *(-1)

   -$x^{2}$=8 => -x=2$\sqrt{2}$ | *(-1) => x=$-2\sqrt{2}$