Flowchart proof- given: line a is parallel to line b, and angle 7 is congruent to angle 10 prove: line c is parallel to line d and use the correct postulates and theorems for reasons.

Determine the common ratio and find the next three terms of the geometric sequence. 649-14-02-00-00_files/i0100000, 649-14-02-00-00_files/i0100001, 2, a. 3; 649-14-02-00-00_files/i0100002, 649-14-02-00-00_files/i0100003, 649-14-02-00-00_files/i0100004. c. 649-14-02-00-00_files/i0100005; 649-14-02-00-00_files/i0100006, 649-14-02-00-00_files/i0100007, 649-14-02-00-00_files/i0100008. b. 3; 6, 18, 54 d. 649-14-02-00-00_files/i0100009. 6, 18, 54 select the best answer from the choices provided a b c d

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9