Respuesta :
Answer:
x=12
Step-by-step explanation:
This is the triangle similarity theorem. First, you make a proportion:
------------------------------------------------------------------------------------
and then solve: 21=x-9
which becomes x=12
Answer:
x=12
Step-by-step explanation:
This is the triangle similarity theorem. First, you make a proportion:
------------------------------------------------------------------------------------
and then solve: 21=x-9
which becomes x=12