The simplest answer form would be -5 square root of 7 end root + 7 square roots of 6
Attached the solution and work. I think this is what you asked for.
Answer:
Option b.
Step-by-step explanation:
Given :
is right angled triangle . An altitude is drawn from point R to point T on side S Q to form a right angle. The length of S T is 9 and the length of T Q is 16. The length of S R is x.
In the figure,
and RT is perpendicular to SQ.
We know that in a right angled triangle if a perpendicular is drawn from the vertex of the right angle to the hypotenuse then triangles on both sides of the perpendicular are similar to each other and to the whole triangle .
Therefore , 
Also, we know that if two triangles are similar then their sides are proportional .

So, option b. is correct
I do not under stand need more info