Question 1052421
{{{M[5]+M[6]=180}}}
and
{{{M[5]=8+3M[6]}}}
Substituting,
{{{8+3M[6]+M[6]=180}}}
{{{4M[6]=172}}}
{{{M[6]=43}}}
Then,
{{{M[5]+43=180}}}
{{{M[5]=137}}}