You are supposed to just keep repeating the stuff in the parenthesis until you get to the end (of the row), at which point you will have 50 stitches.
The stuff in the parenthesis means to knit 3, then increase in the next stitch, just like Sue described above.
Mommy to two wonderful girls
"I don't have to conform to the vagaries of time and space, I'm a loony!" -Campbell Bain (David Tennant) 'Takin' Over the Asylum'
OTN: Cabled Sweater
, arm warmers, kids' clothes