Step-by-step explanation:
[tex]In \: \triangle HDT, \: BM || DT.. (given) \\ \\ \therefore \: \frac{HM}{MT} = \frac{ HB}{ BD} \\ (by \: basic \: proportionality \: theorem) \\ \therefore \: \frac{6}{x} = \frac{9}{15} \\ \\ \therefore \: x= \frac{15 \times 6}{9} \\ \\ \therefore \: x= \frac{90}{9} \\ \\ \therefore \: x= 10 \\ \\ [/tex]
