The answer is 15 trust me.
Answer:
-1
Step-by-step explanation:
The common difference is the constant amount of change between the numbers in an arithmetic sequence.
To find the common difference, you take the last term and subtract it by the previous term.

Answer:
one , i guess....
because the conjecture is only true if it satisfies all the cases.
-- If the 55° angle is one of the two equal angles, then
the third angle is 70° .
-- If the 55° angle is the third angle, then each of the two
equal angles is 62.5° .
-- For either of these cases, there are an infinite number
of possible sets of side-lengths.
The statement in the question does not hold water.