Answer:
d. 8°
Step-by-step explanation:
It appears as though you intend ∠ECF and ∠ACB to be vertical angles, hence the same measure, 47°. The angle of interest, ∠BCD, is added to that to make ∠ACD, which is 55°. The added angle must be 55° -47° = 8°.
=x(x-1) +3x
= x^2-x+3x
=x^2 +2x
=x(x+2)
B, 2,010
Hope this helps have a nice day/night :)