Question

Вирішіть будь ласка.

Answer 1

$1,44-x^2=0\Rightarrow 1,44=x^2\Rightarrow x=\pm\sqrt{1,44} \Rightarrow x=\pm 1,2\Rightarrow x_1=-1,2~;~x_2=1,2. \\\displaystyle\frac{4}{9} -x^2=0~~~\bigg|\cdot9\Rightarrow 4-9x^2=0\Rightarrow -9x^2=-4~~~\bigg|:(-9)\Rightarrow x^2=\frac{4}{9} \Rightarrow x=\pm\sqrt{\frac{4}{9} } \Rightarrow x=\pm\frac{2}{3} \Rightarrow x_1=-\frac{2}{3} ~;~x_2=\frac{2}{3} .\\\frac{25}{36} -x^2=0~~~\bigg|\cdot36\Rightarrow 25-36x^2=0\Rightarrow -36x^2=-25~~~\bigg|:(-36)\Rightarrow x^2=\frac{25}{36} \Rightarrow$

$x_1=-\displaystyle\frac{5}{6} ~;~x_2=\frac{5}{6} .$