First factor the numerator and denominator.
\17 = 1 · 17 \ \
\51 = 3 · 17 \ \
\\
The GCF is the product of the common prime factors in each term.
\GCF = 17
\
Divide the numerator and the denominator by GCF.
\ (Simplify)
\
Simplifest form of the fraction is
.