[tex]x^2=\dfrac{121}{196}\iff x=\pm\sqrt{\dfrac{121}{196}}\\\\x=-\dfrac{\sqrt{121}}{\sqrt{196}}\ \vee\ x=\dfrac{\sqrt{121}}{\sqrt{196}}\\\\\boxed{x=-\dfrac{11}{14}\ \vee\ x=\dfrac{11}{14}}\\\\\sqrt{a}=b\iff b^2=a\\\\\sqrt{121}=11\ \text{because}\ 11^2=121\\\\\sqrt{196}=14\ \text{because}\ 14^2=196[/tex]