Question 1140215
They converted feet to yards
The equation isn't correct and also
they mixed units ( not allowed ) 
[ yds ] = [ ft/3 ]
You could convert to yards immediately
{{{ 42/3 = 14 }}} yds
{{{ 24/3 = 8 }}} yds
{{{ 2*14 + 2*8 = 28 + 16 }}}
{{{ 28 + 16 = 44 }}} yds