Question 951138
{{{J=2M}}}
{{{J^2+M^2=125}}}
Substituting,
{{{(2M)^2+M^2=125}}}
{{{4M^2+M^2=125}}}
{{{5M^2=125}}}
{{{M^2=25}}}
{{{M=5}}}
So then,
{{{J=2(5)}}}
{{{J=10}}}