Question 944706
Jack = j
Lacy = l

{{{j=3l}}}
{{{(j+9)+(l+9)=70}}}
use substitution method
{{{(3l+l)+9+9=70}}}
add like terms
{{{(4l)+18=70}}}
subtract 9
{{{4l=52}}}
divide by 4
{{{l=13}}}
substitute to find j
{{{j=3(13)}}}
{{{j=39}}}