Question 831275
1.{{{J=M+3}}}
2.{{{J+M=45}}}
Substitute eq. 1 into eq. 2,
{{{(M+3)+M=45}}}
{{{2M+3=45}}}
{{{2M=42}}}
{{{highlight(M=21)}}}
Then from eq. 1,
{{{J=M+3}}}
{{{highlight(J=24)}}}