Question

If PQ = x – 5, QR = 2x – 1, and PR = 21, find x. x =

Answer 1

Let $PQ = x - 5,\ QR = 2x - 1,$ and $PR = 21.$ Taking into account that $PR=PQ+QR,$ we get that $x-5+2x-1=21,$ and hence $3x=27.$ It follows that $x=9.$