Question

9xpatrat - 1 = 0 . 5xpatrat + radical din 7 ori x = 0 . 2xpatrat -25 egal cu 0

Answer 1

9x^2-1=0
9x^2=1
x^2=1/9
x=-1/3
x=1/3

5x^2+√7 *x=0
x(5x+√7)=0
x=0
x=-√7/5

2x^2-25=0
2x^2=25
x^2=25/2
x=√25/2
x=5√2/2
x=-5√2/2

Answer 2

   
[tex]\displaystyle 1) \\ 9 x^{2} -1=0 \\ 9 x^{2} =1 \\ x^2= \frac{1}{9} \\ x= \pm \sqrt{\frac{1}{9}} = \pm \frac{1}{3} \\ \\ 2) \\ 5x^2+ \sqrt{7}x = 0 \\ x(5x + \sqrt{7}) =0 \\ x_1 = 0 \\ \\ x_2 = -\frac{ \sqrt{7} }{5} \\ \\ \\ 3) \\ 2x^2-25=0 \\ x^2 = \frac{25}{2} \\ x= \pm \sqrt{ \frac{25}{2}} = \pm \frac{5}{ \sqrt{2} } = \pm \frac{5\sqrt{2}}{2 } [/tex]