PQ=6x+25 and QR=16-3x; Find PR.

Answer 1

Assuming P, Q, and R are collinear in and that order:

PR = 3x + 41

Answer 2

One theorem you should have studied is the Segment Addition Postulate which says: For A, B, & C on a segment, if B is between A & C, then the length of segment AB + the length of segment BC = the length of segment AC.

So, in your case, the length of segment PQ + the length of segment QR = the length of segment PR and since PQ = "6x + 25" and QR = "16 - 3x" then:

(6x + 25) + (16 - 3x) = the length of PR. So, combining like terms, we can say the the length of segment PR = 3x + 41

Without any other information, that's as far as you can go.