To represent the problem in the equation form \( px + q = r \), where:
- \( p \) is the amount saved each week (which is $19),
- \( x \) is the number of weeks,
- \( q \) is the initial amount ($50),
- and \( r \) is the target amount ($259),
the correct equation would be:
\[ 19x + 50 = 259 \]
So the answer is:
19x + 50 = 259 (19 x plus 50 equals 259)