Answer:
RX=4
Explanation:
We are given:
RT = 6 and RS = 9
As RTS is a right angled triangle such that side RS is the hypotenuse of ΔRTS.
Hence on using the Pythagorean theorem we calculate the length of the side TS.

Now again in Right triangle TXS let the length of side SX be 'x'.
Now using Pythagorean Theorem in ΔTXS we have:

As

Now again using Pythagorean theorem in triangle TXR we have:

Hence, the length of side RX=9-5=4
RX=4