Answer:
13
Step-by-step explanation:
[tex]In\: \triangle TVW, \: VW ||SU... (given) \\ \\
\therefore
\frac{TV} {VS} = \frac{TW} {WU} \\(By \: basic \: Proportionality \: Theorem) \\ \\ \therefore \frac{14}{6} = \frac{21}{x - 4} \\ \\ \therefore \: x - 4 = \frac{21 \times 6}{14} \\ \\ \therefore \: x - 4 = \frac{3 \times 6}{2} \\ \\ \therefore \: x - 4 = 3 \times 3 \\ \\ \therefore \: x - 4 = 9 \\ \\ \therefore \: x = 9 + 4 \\ \\ \huge \red{ \boxed{\therefore \: x = 13}} \\ [/tex]
