You need to learn where your root note is within each scale position for ether the minor, or major pentatonic scale. For instance the G major pentatonic scale has all the same notes as the E minor pentatonic scale BUT the root note changes position. Note the highlighted root on the following scales:

G major: http://www.all-guitar-chords.com/guitar_scales.php?scch=G&scchnam=Pentatonic+Major&get2=Get&t=0&choice=1

E minor: http://www.all-guitar-chords.com/guitar_scales.php?scch=E&scchnam=Pentatonic+Minor&get2=Get&t=0&choice=1

See, they're the same, but the root changes position in the scale pattern depending on if it's major or minor. If you know your positions, now you have to learn the position of the root note within the scales. Now using E minor pentatonic as an example, position 1 starts at the open low E (which is your root note and the key you're in) and gos 0-3, 0-2, 0-2, 0-2, 0-3, 0-3. Learning where the root note is within the scale is as important as knowing the scale pattern.