Respuesta :

SvetlanaM

Answer: 15

Step-by-step explanation:

[tex]\dfrac{ST}{VW} =\dfrac{SR}{VU} \\\\ST=21\\VW=30\\SR=21\\VU=42\\\\\dfrac{x}{30} =\dfrac{21}{42} \\\\x \times 42=21 \times 30\\x \times 42=630\\x \times 42 \div 42=630 \div 42\\x=15[/tex]