Question 1052381
{{{D+Q=18}}}
and
{{{10D+25Q=330}}}
{{{2D+5Q=66}}}
From above,
{{{2D+2Q=36}}}
Subtracting,
{{{2D+5Q-2D-2Q=66-36}}}
{{{3Q=30}}}
{{{Q=10}}}
So then,
{{{D+10=18}}}
{{{D=8}}}