Question

Find the GCD:

(1) 90, 50

Answer 1

$\begin{array}{cc}2& 90\\ 3& 45\\ 3& 15\\ 5& 5\\ & 1\end{array}$
⇒ 90 = 2 × 3 × 3 × 5

$\begin{array}{cc}2& 50\\ 5& 25\\ 5& 5\\ & 1\end{array}$
⇒ 50 = 2 × 5 × 5

∴ GCD = 2 × 5 = 10