What is the value of x?

Answer:
x = 22.5
Step-by-step explanation:
[tex] \frac{BH}{DH} = \frac{HM}{HT} \\ \frac{6}{15 + 6} = \frac{9}{9 + x} \\ \frac{6}{21} = \frac{9}{9 + x} \\ 6(9 + x) = 9 \times 21 \\ 54 + 6x = 189 \\ 6x = 189 - 54 \\ 6x = 135 \\ x = \frac{135}{6} \\ x = 22.5[/tex]