Answer:
Correct choice is B
Step-by-step explanation:
In step 4 were proved that 
By definition, similar triangles have proportional lengths of corresponding sides. To the side AB corresponds side ED, to the side AC corresponds side DC and to the side BC corresponds side EC. Thus,

Answer:
30
Step-by-step explanation:
Answer:
x=-7
Step-by-step explanation:
Subtract 5 from both sides.
−x=12−5
Subtract 5 from 12 to get 7.
−x=7
Multiply both sides by −1.
x=−7
Answer:
X=6 I believe
Step-by-step explanation: