What is the value of x enter your answe in the box

i had this question on a quiz a while back i am homeschooled and i beleive the answer was 17
Answer:
x = 27.
Step-by-step explanation:
Since QC is parallel to BR, by the Triangular Proportionality Theorem:
39/26 = x / 18
3/2 = x / 18
x = 3*18 / 2
x = 27 (answer).