Question

81 х в квадрате - 9 = 0

Answer 1

$81x^{2}-9=0$

$81x^{2}=9$

$x^{2}=9:81$

$x^{2}=frac{9}{81}=frac{1}{9}$

$x_{1}=sqrt{frac{1}{9}}=frac{1}{3}$

 

$x_{2}=-sqrt{frac{1}{9}}=-frac{1}{3}$

 

Answer 2

81х² - 9 = 0

81х² = 9

х² = 1/9

х1 = - √1/9 = -1/3

х2 = √1/9 = 1/3