Question

Решите подробно пожалуйста

Answer 1

$7x^2=frac1{63} \\ x^2=frac1{63}:7 \\ x^2=frac1{441} \\ x=sqrt frac{1}{441}=sqrt frac {1^2}{21^2}=frac1{21}$

Answer 2

7x^2= 167
x^2= 167 7
x^2= 1441
x= `121