Review question

Given this equation, what's the value of $a+b+c+d$? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R6219

Question

Four positive integers $a$, $b$, $c$ and $d$ are such that

$abcd+abc+bcd+cda+dab+ab+bc+cd+da+ac+bd+a+b+c+d=2009.$

What is the value of $a+b+c+d$?