The formula for any geometric sequence is a n = a 1 · r n - 1, where a n represents the value of the nth term, a 1 represents the value of the first term, r represents the common ratio, and n represents the term number. what is the formula for the sequence -3, -6, -12, -24, an = -3 · 2n - 1 an = -3 · (-2)n - 1 an = 2 · (-3)n - 1 an = -2 · (-3)n - 1

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap